1
|
Fraga OT, Silva LAC, Silva JCF, Bevitori R, Silva FDA, Pereira WA, Reis PAB, Fontes EPB. Expansion and diversification of the Glycine max (Gm) ERD15-like subfamily of the PAM2-like superfamily. PLANTA 2024; 260:108. [PMID: 39333439 DOI: 10.1007/s00425-024-04538-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 09/22/2024] [Indexed: 09/29/2024]
Abstract
MAIN CONCLUSION Despite modulating senescence and drought responses, the GmERD15-like subfamily members are differentially induced by multiple stresses and diverge partially in stress signaling functions. The PAM2 motif represents a binding site for poly (A)-binding proteins (PABPs), often associated with RNA metabolism regulation. The PAM2-containing protein ERD15 stands out as a critical regulator of diverse stress responses in plants. Despite the relevance of the PAM2 motif, a comprehensive analysis of the PAM2 superfamily and ERD15-like subfamily in the plant kingdom is lacking. Here, we provide an extensive in silico analysis of the PAM2 superfamily and the ERD15-like subfamily in soybean, using Arabidopsis and rice sequences as prototypes. The Glycine max ERD15-like subfamily members were clustered in pairs, likely originating from DNA-based gene duplication, as the paralogs display high sequence conservation, similar exon/intron genome organization, and are undergoing purifying selection. Complementation analyses of an aterd15 mutant demonstrated that the plant ERD15-like subfamily members are functionally redundant in response to drought, osmotic stress, and dark-induced senescence. Nevertheless, the soybean members displayed differential expression profiles, biochemical activity, and subcellular localization, consistent with functional diversification. The expression profiles of Glyma04G138600 under salicylic acid (SA) and abscisic acid (ABA) treatments differed oppositely from those of the other GmERD15-like genes. Abiotic stress-induced coexpression analysis with soybean PABPs showed that Glyma04G138600 was clustered separately from other GmERD15s. In contrast to the AtERD15 stress-induced nuclear redistribution, Glyma04G138600 and Glyma02G260800 localized to the cytoplasm, while Glyma03G131900 fractionated between the cytoplasm and nucleus under normal and stress conditions. These data collectively indicate that despite modulating senescence and drought responses, the GmERD15-like subfamily members are differentially induced by multiple stresses and may diverge partially in stress signaling functions.
Collapse
Affiliation(s)
- Otto T Fraga
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil
| | - Lucas A C Silva
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil
| | - José Cleydson F Silva
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil
| | - Rosângela Bevitori
- Biotechnology Laboratory, Embrapa Rice and Beans, Rodovia GO-462, Km 12, Santo Antônio de Goiás, GO, 75375-000, Brazil
| | - Fredy D A Silva
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil
| | - Welison A Pereira
- Department of Biology, Universidade Federal de Lavras, Lavras, 37200-900, Brazil
| | - Pedro A B Reis
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil.
| | - Elizabeth P B Fontes
- Department of Biochemistry and Molecular Biology, BIOAGRO, National Institute of Science and Technology in Plant-Pest Interactions, Universidade Federal de Viçosa, Viçosa, MG, 36571.000, Brazil.
| |
Collapse
|
2
|
Zaninello M, Schlegel T, Nolte H, Pirzada M, Savino E, Barth E, Klein I, Wüstenberg H, Uddin T, Wolff L, Wirth B, Lehmann HC, Cioni JM, Langer T, Rugarli EI. CLUH maintains functional mitochondria and translation in motoneuronal axons and prevents peripheral neuropathy. SCIENCE ADVANCES 2024; 10:eadn2050. [PMID: 38809982 PMCID: PMC11135423 DOI: 10.1126/sciadv.adn2050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 04/24/2024] [Indexed: 05/31/2024]
Abstract
Transporting and translating mRNAs in axons is crucial for neuronal viability. Local synthesis of nuclear-encoded mitochondrial proteins protects long-lived axonal mitochondria from damage; however, the regulatory factors involved are largely unknown. We show that CLUH, which binds mRNAs encoding mitochondrial proteins, prevents peripheral neuropathy and motor deficits in the mouse. CLUH is enriched in the growth cone of developing spinal motoneurons and is required for their growth. The lack of CLUH affects the abundance of target mRNAs and the corresponding mitochondrial proteins more prominently in axons, leading to ATP deficits in the growth cone. CLUH interacts with ribosomal subunits, translation initiation, and ribosome recycling components and preserves axonal translation. Overexpression of the ribosome recycling factor ABCE1 rescues the mRNA and translation defects, as well as the growth cone size, in CLUH-deficient motoneurons. Thus, we demonstrate a role for CLUH in mitochondrial quality control and translational regulation in axons, which is essential for their development and long-term integrity and function.
Collapse
Affiliation(s)
- Marta Zaninello
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
| | - Tim Schlegel
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
| | - Hendrik Nolte
- Max Planck Institute for Biology of Ageing, Cologne 50931, Germany
| | - Mujeeb Pirzada
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
| | - Elisa Savino
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Esther Barth
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
| | - Ines Klein
- Department of Neurology, University of Cologne, Cologne 50931, Germany
| | - Hauke Wüstenberg
- Department of Neurology, University of Cologne, Cologne 50931, Germany
| | - Tesmin Uddin
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
| | - Lisa Wolff
- Institute of Human Genetics, University of Cologne, Cologne 50931, Germany
| | - Brunhilde Wirth
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Institute of Human Genetics, University of Cologne, Cologne 50931, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne 50931, Germany
- Center for Rare Diseases Cologne (CESEK), University Hospital of Cologne, Cologne 50937, Germany
| | - Helmar C. Lehmann
- Department of Neurology, University of Cologne, Cologne 50931, Germany
| | - Jean-Michel Cioni
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan 20132, Italy
| | - Thomas Langer
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
- Max Planck Institute for Biology of Ageing, Cologne 50931, Germany
| | - Elena I. Rugarli
- Institute for Genetics, University of Cologne, Cologne 50931, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne 50931, Germany
- Center for Molecular Medicine (CMMC), University of Cologne, Cologne 50931, Germany
| |
Collapse
|
3
|
Schneider KL, Hao X, Keuenhof KS, Berglund LL, Fischbach A, Ahmadpour D, Chawla S, Gómez P, Höög JL, Widlund PO, Nyström T. Elimination of virus-like particles reduces protein aggregation and extends replicative lifespan in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 2024; 121:e2313538121. [PMID: 38527193 PMCID: PMC10998562 DOI: 10.1073/pnas.2313538121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 02/04/2024] [Indexed: 03/27/2024] Open
Abstract
A major consequence of aging and stress, in yeast to humans, is an increased accumulation of protein aggregates at distinct sites within the cells. Using genetic screens, immunoelectron microscopy, and three-dimensional modeling in our efforts to elucidate the importance of aggregate annexation, we found that most aggregates in yeast accumulate near the surface of mitochondria. Further, we show that virus-like particles (VLPs), which are part of the retrotransposition cycle of Ty elements, are markedly enriched in these sites of protein aggregation. RNA interference-mediated silencing of Ty expression perturbed aggregate sequestration to mitochondria, reduced overall protein aggregation, mitigated toxicity of a Huntington's disease model, and expanded the replicative lifespan of yeast in a partially Hsp104-dependent manner. The results are in line with recent data demonstrating that VLPs might act as aging factors in mammals, including humans, and extend these findings by linking VLPs to a toxic accumulation of protein aggregates and raising the possibility that they might negatively influence neurological disease progression.
Collapse
Affiliation(s)
- K. L. Schneider
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - X. Hao
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - K. S. Keuenhof
- Department for Chemistry and Molecular Biology, University of Gothenburg, Gothenburg41390, Sweden
| | - L. L. Berglund
- Department for Chemistry and Molecular Biology, University of Gothenburg, Gothenburg41390, Sweden
| | - A. Fischbach
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - D. Ahmadpour
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - S. Chawla
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - P. Gómez
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - J. L. Höög
- Department for Chemistry and Molecular Biology, University of Gothenburg, Gothenburg41390, Sweden
| | - P. O. Widlund
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| | - T. Nyström
- Department of Microbiology and Immunology, Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health—AgeCap, University of Gothenburg, Gothenburg40530, Sweden
| |
Collapse
|
4
|
Lewis BM, Cho CY, Her HL, Mizrahi O, Hunter T, Yeo GW. LARP4 is an RNA-binding protein that binds nuclear-encoded mitochondrial mRNAs to promote mitochondrial function. RNA (NEW YORK, N.Y.) 2024; 30:223-239. [PMID: 38164626 PMCID: PMC10870378 DOI: 10.1261/rna.079799.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/25/2023] [Indexed: 01/03/2024]
Abstract
Mitochondria-associated RNA-binding proteins (RBPs) have emerged as key contributors to mitochondrial biogenesis and homeostasis. With few examples known, we set out to identify RBPs that regulate nuclear-encoded mitochondrial mRNAs (NEMmRNAs). Our systematic analysis of RNA targets of 150 RBPs identified RBPs with a preference for binding NEMmRNAs, including LARP4, a La RBP family member. We show that LARP4's targets are particularly enriched in mRNAs that encode respiratory chain complex proteins (RCCPs) and mitochondrial ribosome proteins (MRPs) across multiple human cell lines. Through quantitative proteomics, we demonstrate that depletion of LARP4 leads to a significant reduction in RCCP and MRP protein levels. Furthermore, we show that LARP4 depletion reduces mitochondrial function, and that LARP4 re-expression rescues this phenotype. Our findings shed light on a novel function for LARP4 as an RBP that binds to and positively regulates NEMmRNAs to promote mitochondrial respiratory function.
Collapse
Affiliation(s)
- Benjamin M Lewis
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Chae Yun Cho
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Hsuan-Lin Her
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, California 92037, USA
| | - Orel Mizrahi
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, California 92037, USA
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, California 92037, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, California 92037, USA
- Stem Cell Program, University of California San Diego, La Jolla, California 92037, USA
| |
Collapse
|
5
|
Sen A, Cox RT. Loss of Drosophila Clueless differentially affects the mitochondrial proteome compared to loss of Sod2 and Pink1. Front Physiol 2022; 13:1004099. [DOI: 10.3389/fphys.2022.1004099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondria contain their own DNA, mitochondrial DNA, which encodes thirteen proteins. However, mitochondria require thousands of proteins encoded in the nucleus to carry out their many functions. Identifying the definitive mitochondrial proteome has been challenging as methods isolating mitochondrial proteins differ and different tissues and organisms may have specialized proteomes. Mitochondrial diseases arising from single gene mutations in nucleus encoded genes could affect the mitochondrial proteome, but deciphering which effects are due to loss of specific pathways or to accumulated general mitochondrial damage is difficult. To identify specific versus general effects, we have taken advantage of mutations in three Drosophila genes, clueless, Sod2, and Pink1, which are required for mitochondrial function through different pathways. We measured changes in each mutant’s mitochondrial proteome using quantitative tandem mass tag mass spectrometry. Our analysis identified protein classes that are unique to each mutant and those shared between them, suggesting that some changes in the mitochondrial proteome are due to general mitochondrial damage whereas others are gene specific. For example, clueless mutants had the greatest number of less and more abundant mitochondrial proteins whereas loss of all three genes increased stress and metabolism proteins. This study is the first to directly compare in vivo steady state levels of mitochondrial proteins by examining loss of three pathways critical for mitochondrial function. These data could be useful to understand disease etiology, and how mutations in genes critical for mitochondrial function cause specific mitochondrial proteomic changes as opposed to changes due to generalized mitochondrial damage.
Collapse
|
6
|
Ralevski A, Apelt F, Olas JJ, Mueller-Roeber B, Rugarli EI, Kragler F, Horvath TL. Plant mitochondrial FMT and its mammalian homolog CLUH controls development and behavior in Arabidopsis and locomotion in mice. Cell Mol Life Sci 2022; 79:334. [PMID: 35652974 PMCID: PMC11071973 DOI: 10.1007/s00018-022-04382-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 11/26/2022]
Abstract
Mitochondria in animals are associated with development, as well as physiological and pathological behaviors. Several conserved mitochondrial genes exist between plants and higher eukaryotes. Yet, the similarities in mitochondrial function between plant and animal species is poorly understood. Here, we show that FMT (FRIENDLY MITOCHONDRIA) from Arabidopsis thaliana, a highly conserved homolog of the mammalian CLUH (CLUSTERED MITOCHONDRIA) gene family encoding mitochondrial proteins associated with developmental alterations and adult physiological and pathological behaviors, affects whole plant morphology and development under both stressed and normal growth conditions. FMT was found to regulate mitochondrial morphology and dynamics, germination, and flowering time. It also affects leaf expansion growth, salt stress responses and hyponastic behavior, including changes in speed of hyponastic movements. Strikingly, Cluh± heterozygous knockout mice also displayed altered locomotive movements, traveling for shorter distances and had slower average and maximum speeds in the open field test. These observations indicate that homologous mitochondrial genes may play similar roles and affect homologous functions in both plants and animals.
Collapse
Affiliation(s)
- Alexandra Ralevski
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA
- Yale Center for Molecular and Systems Metabolism, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Federico Apelt
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476, Potsdam, Germany
| | - Justyna J Olas
- Department of Molecular Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476, Potsdam, Germany
| | - Bernd Mueller-Roeber
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476, Potsdam, Germany
- Department of Molecular Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476, Potsdam, Germany
| | - Elena I Rugarli
- Department of Biology, Institute for Genetics, University of Cologne, Cologne, Germany
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Friedrich Kragler
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, 14476, Potsdam, Germany
| | - Tamas L Horvath
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, 06520, USA.
- Yale Center for Molecular and Systems Metabolism, Yale University School of Medicine, New Haven, CT, 06520, USA.
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
- Department of Neuroscience and Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT, 06520, USA.
| |
Collapse
|
7
|
Yang H, Sibilla C, Liu R, Yun J, Hay BA, Blackstone C, Chan DC, Harvey RJ, Guo M. Clueless/CLUH regulates mitochondrial fission by promoting recruitment of Drp1 to mitochondria. Nat Commun 2022; 13:1582. [PMID: 35332133 PMCID: PMC8948191 DOI: 10.1038/s41467-022-29071-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/04/2022] [Indexed: 02/08/2023] Open
Abstract
Mitochondrial fission is critically important for controlling mitochondrial morphology, function, quality and transport. Drp1 is the master regulator driving mitochondrial fission, but exactly how Drp1 is regulated remains unclear. Here, we identified Drosophila Clueless and its mammalian orthologue CLUH as key regulators of Drp1. As with loss of drp1, depletion of clueless or CLUH results in mitochondrial elongation, while as with drp1 overexpression, clueless or CLUH overexpression leads to mitochondrial fragmentation. Importantly, drp1 overexpression rescues adult lethality, tissue disintegration and mitochondrial defects of clueless null mutants in Drosophila. Mechanistically, Clueless and CLUH promote recruitment of Drp1 to mitochondria from the cytosol. This involves CLUH binding to mRNAs encoding Drp1 receptors MiD49 and Mff, and regulation of their translation. Our findings identify a crucial role of Clueless and CLUH in controlling mitochondrial fission through regulation of Drp1. Drp1 is the master regulator of mitochondrial fission, which has important impact on cellular functions. Here, Yang et al identified evolutionarily conserved proteins Clueless and its homolog CLUH as key regulators of Drp1 that function via translation of Drp1 receptors MiD49 and Mff.
Collapse
Affiliation(s)
- Huan Yang
- Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA
| | - Caroline Sibilla
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.,Department of Pharmacology, University College London School of Pharmacy, London, UK.,AstraZeneca PLC, Cambridge Biomedical Campus, Cambridge, UK
| | - Raymond Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.,Department of Microbiology and Immunology, UCSF, San Francisco, CA, USA
| | - Jina Yun
- Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA.,Genentech, Inc., South San Francisco, CA, USA
| | - Bruce A Hay
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.,Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - David C Chan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Robert J Harvey
- School of Health and Behavioural Sciences, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,Sunshine Coast Health Institute, Birtinya, QLD, Australia
| | - Ming Guo
- Department of Neurology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA. .,Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA, USA. .,California NanoSystems Institute at UCLA, Los Angeles, CA, USA.
| |
Collapse
|
8
|
Tsai CY, Chiou SJ, Ko HJ, Cheng YF, Lin SY, Lai YL, Lin CY, Wang C, Cheng JT, Liu HF, Kwan AL, Loh JK, Hong YR. Deciphering the evolution of composite-type GSKIP in mitochondria and Wnt signaling pathways. PLoS One 2022; 17:e0262138. [PMID: 35051222 PMCID: PMC8775565 DOI: 10.1371/journal.pone.0262138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 12/16/2021] [Indexed: 11/30/2022] Open
Abstract
We previously revealed the origin of mammalian simple-type glycogen synthase kinase interaction protein (GSKIP), which served as a scavenger and a competitor in the Wnt signaling pathway during evolution. In this study, we investigated the conserved and nonconserved regions of the composite-type GSKIP by utilizing bioinformatics tools, site-directed mutagenesis, and yeast two-hybrid methods. The regions were denoted as the pre-GSK3β binding site, which is located at the front of GSK3β-binding sites. Our data demonstrated that clustered mitochondria protein 1 (CLU1), a type of composite-type GSKIP that exists in the mitochondria of all eukaryotic organisms, possesses the protein known as domain of unknown function 727 (DUF727), with a pre-GSK3β-binding site and a mutant GSK3β-binding flanking region. Another type of composite-type GSKIP, armadillo repeat containing 4 (ARMC4), which is known for cilium movement in vertebrates, contains an unintegrated DUF727 flanking region with a pre-GSK3β-binding site (115SPxF118) only. In addition, the sequence of the GSK3β-binding site in CLU1 revealed that Q126L and V130L were not conserved, differing from the ideal GSK3β-binding sequence of simple-type GSKIP. We further illustrated two exceptions, namely 70 kilodalton heat shock proteins (Hsp70/DnaK) and Mitofilin in nematodes, that presented an unexpected ideal GSK3β-binding region with a pre-GSK3β sequence; this composite-type GSKIP could only occur in vertebrate species. Furthermore, we revealed the importance of the pre-GSK3β-binding site (118F or 118Y) and various mutant GSK3β-binding sites of composite-type GSKIP. Collectively, our data suggest that the new composite-type GSKIP starts with a DUF727 domain followed by a pre-GSK3β-binding site, with the subsequent addition of the GSK3β-binding site, which plays vital roles for CLU1, Mitofilin, and ARMC4 in mitochondria and Wnt signaling pathways during evolution.
Collapse
Affiliation(s)
- Cheng-Yu Tsai
- College of Medicine, Kaohsiung Medical University and National Health Research Institutes, Kaohsiung, Taiwan
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Shean-Jaw Chiou
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Huey-Jiun Ko
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yu-Fan Cheng
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Sin-Yi Lin
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yun-Ling Lai
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chen-Yen Lin
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chihuei Wang
- Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jiin-Tsuey Cheng
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Hsin-Fu Liu
- Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan
| | - Aij-Li Kwan
- College of Medicine, Kaohsiung Medical University and National Health Research Institutes, Kaohsiung, Taiwan
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Joon-Khim Loh
- Department of Neurosurgery, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- * E-mail: (YRH); (JKL)
| | - Yi-Ren Hong
- College of Medicine, Kaohsiung Medical University and National Health Research Institutes, Kaohsiung, Taiwan
- Department of Biochemistry, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung, Taiwan
- * E-mail: (YRH); (JKL)
| |
Collapse
|
9
|
Hémono M, Haller A, Chicher J, Duchêne AM, Ngondo RP. The interactome of CLUH reveals its association to SPAG5 and its co-translational proximity to mitochondrial proteins. BMC Biol 2022; 20:13. [PMID: 35012549 PMCID: PMC8744257 DOI: 10.1186/s12915-021-01213-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/14/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Mitochondria require thousands of proteins to fulfill their essential function in energy production and other fundamental biological processes. These proteins are mostly encoded by the nuclear genome, translated in the cytoplasm before being imported into the organelle. RNA binding proteins (RBPs) are central players in the regulation of this process by affecting mRNA translation, stability, or localization. CLUH is an RBP recognizing specifically mRNAs coding for mitochondrial proteins, but its precise molecular function and interacting partners remain undiscovered in mammals. RESULTS Here we reveal for the first time CLUH interactome in mammalian cells. Using both co-IP and BioID proximity-labeling approaches, we identify novel molecular partners interacting stably or transiently with CLUH in HCT116 cells and mouse embryonic stem cells. We reveal stable RNA-independent interactions of CLUH with itself and with SPAG5 in cytosolic granular structures. More importantly, we uncover an unexpected proximity of CLUH to mitochondrial proteins and their cognate mRNAs in the cytosol. We show that this interaction occurs during the process of active translation and is dependent on CLUH TPR domain. CONCLUSIONS Overall, through the analysis of CLUH interactome, our study sheds a new light on CLUH molecular function by revealing new partners and by highlighting its link to the translation and subcellular localization of some mRNAs coding for mitochondrial proteins.
Collapse
Affiliation(s)
- Mickaële Hémono
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, Strasbourg, 67084, France
| | - Alexandre Haller
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, Strasbourg, 67084, France
- Université de Strasbourg, CNRS, INSERM, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, U 1258, 1 rue Laurent Fries, 67404, Illkirch, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg Esplanade FR1589 du CNRS, Université de Strasbourg, Strasbourg, France
| | - Anne-Marie Duchêne
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, Strasbourg, 67084, France
| | - Richard Patryk Ngondo
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, 12 rue du Général Zimmer, Strasbourg, 67084, France.
| |
Collapse
|
10
|
Restoring fertility in yeast hybrids: Breeding and quantitative genetics of beneficial traits. Proc Natl Acad Sci U S A 2021; 118:2101242118. [PMID: 34518218 PMCID: PMC8463882 DOI: 10.1073/pnas.2101242118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 11/18/2022] Open
Abstract
Hybrids between species can harbor a combination of beneficial traits from each parent and may exhibit hybrid vigor, more readily adapting to new harsher environments. Interspecies hybrids are also sterile and therefore an evolutionary dead end unless fertility is restored, usually via auto-polyploidisation events. In the Saccharomyces genus, hybrids are readily found in nature and in industrial settings, where they have adapted to severe fermentative conditions. Due to their hybrid sterility, the development of new commercial yeast strains has so far been primarily conducted via selection methods rather than via further breeding. In this study, we overcame infertility by creating tetraploid intermediates of Saccharomyces interspecies hybrids to allow continuous multigenerational breeding. We incorporated nuclear and mitochondrial genetic diversity within each parental species, allowing for quantitative genetic analysis of traits exhibited by the hybrids and for nuclear-mitochondrial interactions to be assessed. Using pooled F12 generation segregants of different hybrids with extreme phenotype distributions, we identified quantitative trait loci (QTLs) for tolerance to high and low temperatures, high sugar concentration, high ethanol concentration, and acetic acid levels. We identified QTLs that are species specific, that are shared between species, as well as hybrid specific, in which the variants do not exhibit phenotypic differences in the original parental species. Moreover, we could distinguish between mitochondria-type-dependent and -independent traits. This study tackles the complexity of the genetic interactions and traits in hybrid species, bringing hybrids into the realm of full genetic analysis of diploid species, and paves the road for the biotechnological exploitation of yeast biodiversity.
Collapse
|
11
|
Nakamura S, Hagihara S, Otomo K, Ishida H, Hidema J, Nemoto T, Izumi M. Autophagy Contributes to the Quality Control of Leaf Mitochondria. PLANT & CELL PHYSIOLOGY 2021; 62:229-247. [PMID: 33355344 PMCID: PMC8112837 DOI: 10.1093/pcp/pcaa162] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/05/2020] [Indexed: 05/11/2023]
Abstract
In autophagy, cytoplasmic components of eukaryotic cells are transported to lysosomes or the vacuole for degradation. Autophagy is involved in plant tolerance to the photooxidative stress caused by ultraviolet B (UVB) radiation, but its roles in plant adaptation to UVB damage have not been fully elucidated. Here, we characterized organellar behavior in UVB-damaged Arabidopsis (Arabidopsis thaliana) leaves and observed the occurrence of autophagic elimination of dysfunctional mitochondria, a process termed mitophagy. Notably, Arabidopsis plants blocked in autophagy displayed increased leaf chlorosis after a 1-h UVB exposure compared to wild-type plants. We visualized autophagosomes by labeling with a fluorescent protein-tagged autophagosome marker, AUTOPHAGY8 (ATG8), and found that a 1-h UVB treatment led to increased formation of autophagosomes and the active transport of mitochondria into the central vacuole. In atg mutant plants, the mitochondrial population increased in UVB-damaged leaves due to the cytoplasmic accumulation of fragmented, depolarized mitochondria. Furthermore, we observed that autophagy was involved in the removal of depolarized mitochondria when mitochondrial function was disrupted by mutation of the FRIENDLY gene, which is required for proper mitochondrial distribution. Therefore, autophagy of mitochondria functions in response to mitochondrion-specific dysfunction as well as UVB damage. Together, these results indicate that autophagy is centrally involved in mitochondrial quality control in Arabidopsis leaves.
Collapse
Affiliation(s)
- Sakuya Nakamura
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
| | - Shinya Hagihara
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
| | - Kohei Otomo
- Exploratory Research Center on Life and Living Systems (ExCELLs), National Institute of Natural Sciences, Okazaki, 444-8787 Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Study (SOKENDAI), Hayama, 240-0193 Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020 Japan
| | - Hiroyuki Ishida
- Department of Applied Plant Science, Graduate School of Agricultural Sciences, Tohoku University, Sendai, 980-0845, Japan
| | - Jun Hidema
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, 980-8577, Japan
| | - Tomomi Nemoto
- Exploratory Research Center on Life and Living Systems (ExCELLs), National Institute of Natural Sciences, Okazaki, 444-8787 Japan
- National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, 444-8787 Japan
- Department of Physiological Sciences, The Graduate University for Advanced Study (SOKENDAI), Hayama, 240-0193 Japan
- Research Institute for Electronic Science, Hokkaido University, Sapporo, 001-0020 Japan
| | - Masanori Izumi
- Center for Sustainable Resource Science (CSRS), RIKEN, Wako, 351-0198 Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, 322-0012 Japan
| |
Collapse
|
12
|
Ayabe H, Kawai N, Shibamura M, Fukao Y, Fujimoto M, Tsutsumi N, Arimura SI. FMT, a protein that affects mitochondrial distribution, interacts with translation-related proteins in Arabidopsis thaliana. PLANT CELL REPORTS 2021; 40:327-337. [PMID: 33385240 DOI: 10.1007/s00299-020-02634-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/06/2020] [Indexed: 06/12/2023]
Abstract
Two translation-related proteins are identified as FMT-interacting proteins. However, FMT, unlike mutants of other CLU genes in fly and human, has no clear impact on the accumulation of mitochondrial proteins. Organelle distribution is critical for effective metabolism and stress response and is controlled by various environmental factors. Clustered mitochondria (CLU) superfamily genes affect mitochondrial distribution and their disruptions cause mitochondria to cluster within a cell in various species including yeast, fly, mammals and Arabidopsis. In Arabidopsis thaliana, Friendly mitochondria (FMT) is a CLU gene that is required for normal mitochondrial distribution, but its molecular function is unclear. Here, we demonstrate that FMT interacts with some translation-related proteins (translation initiation factor eIFiso4G1 and glutamyl-tRNA synthetase OVA9), as well as itself. We also show FMT forms dynamic particles in the cytosol that sometimes move with mitochondria, and their movements are mainly controlled by actin filaments but also by microtubules. Similar results have been reported for animal CLU orthologs. However, an fmt mutant, unlike animal clu mutants, did not show any clear decrease of nuclear-encoded mitochondrial protein levels. This difference may reflect a functional divergence of FMT from other CLU superfamily genes.
Collapse
Affiliation(s)
- Hiroki Ayabe
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan
| | - Narumi Kawai
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan
| | - Mitsuhiro Shibamura
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan
| | - Yoichiro Fukao
- Graduate School of Life Science, Ritsumeikan University, Shiga, Japan
| | - Masaru Fujimoto
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan
| | - Nobuhiro Tsutsumi
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan
| | - Shin-Ichi Arimura
- Graduate School of Agricultural & Life Sciences, University of Tokyo, Tokyo, Japan.
| |
Collapse
|
13
|
Parker DM, Winkenbach LP, Boyson S, Saxton MN, Daidone C, Al-Mazaydeh ZA, Nishimura MT, Mueller F, Osborne Nishimura E. mRNA localization is linked to translation regulation in the Caenorhabditis elegans germ lineage. Development 2020; 147:dev186817. [PMID: 32541012 PMCID: PMC7358130 DOI: 10.1242/dev.186817] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/30/2020] [Indexed: 01/01/2023]
Abstract
Caenorhabditis elegans early embryos generate cell-specific transcriptomes despite lacking active transcription, thereby presenting an opportunity to study mechanisms of post-transcriptional regulatory control. We observed that some cell-specific mRNAs accumulate non-homogenously within cells, localizing to membranes, P granules (associated with progenitor germ cells in the P lineage) and P-bodies (associated with RNA processing). The subcellular distribution of transcripts differed in their dependence on 3'UTRs and RNA binding proteins, suggesting diverse regulatory mechanisms. Notably, we found strong but imperfect correlations between low translational status and P granule localization within the progenitor germ lineage. By uncoupling translation from mRNA localization, we untangled a long-standing question: Are mRNAs directed to P granules to be translationally repressed, or do they accumulate there as a consequence of this repression? We found that translational repression preceded P granule localization and could occur independently of it. Further, disruption of translation was sufficient to send homogenously distributed mRNAs to P granules. These results implicate transcriptional repression as a means to deliver essential maternal transcripts to the progenitor germ lineage for later translation.
Collapse
Affiliation(s)
- Dylan M Parker
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Lindsay P Winkenbach
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Sam Boyson
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Matthew N Saxton
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Camryn Daidone
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Zainab A Al-Mazaydeh
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Department of Biology and Biotechnology, Hashemite University, Zarqa, 13115, Jordan
| | - Marc T Nishimura
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Florian Mueller
- Département Biologie Cellulaire et Infections, Unité Imagerie et Modélisation, Institut Pasteur and CNRS UMR 3691, 28 rue du Docteur Roux, 75015 Paris, France
| | - Erin Osborne Nishimura
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| |
Collapse
|
14
|
Collart MA, Weiss B. Ribosome pausing, a dangerous necessity for co-translational events. Nucleic Acids Res 2020; 48:1043-1055. [PMID: 31598688 PMCID: PMC7026645 DOI: 10.1093/nar/gkz763] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/13/2019] [Accepted: 08/21/2019] [Indexed: 12/31/2022] Open
Abstract
In recent years translation elongation has emerged as an important contributor to the regulation of gene expression. There are multiple quality control checkpoints along the way of producing mature proteins and targeting them to the right cellular compartment, or associating them correctly with their partners. Ribosomes pause to allow co-translational protein folding, protein targeting or protein interactions, and the pausing is dictated by a combination of the mRNA sequence and structure, the tRNA availability and the nascent peptide. However, ribosome pausing can also lead to ribosome collisions and co-translational degradation of both mRNA and nascent chain. Understanding how the translating ribosome tunes the different maturation steps that nascent proteins must undergo, what the timing of these maturation events is, and how degradation can be avoided when pausing is needed, is now possible by the emergence of methods to follow ribosome dynamics in vivo. This review summarizes some of the recent studies that have advanced our knowledge about co-translational events using the power of ribosome profiling, and some of the questions that have emerged from these studies.
Collapse
Affiliation(s)
- Martine A Collart
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Institute of Genetics and Genomics, Geneva, 1 rue Michel Servet, 1211 Genève 4, Switzerland
| | - Benjamin Weiss
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, University of Geneva, Institute of Genetics and Genomics, Geneva, 1 rue Michel Servet, 1211 Genève 4, Switzerland
| |
Collapse
|
15
|
Schatton D, Rugarli EI. A concert of RNA-binding proteins coordinates mitochondrial function. Crit Rev Biochem Mol Biol 2019; 53:652-666. [DOI: 10.1080/10409238.2018.1553927] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Désirée Schatton
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Elena I. Rugarli
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| |
Collapse
|
16
|
The origin of GSKIP, a multifaceted regulatory factor in the mammalian Wnt pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1865:1046-1059. [DOI: 10.1016/j.bbamcr.2018.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 04/13/2018] [Accepted: 04/19/2018] [Indexed: 11/17/2022]
|
17
|
Schatton D, Rugarli EI. Post-transcriptional regulation of mitochondrial function. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2017.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
Midgett M, López CS, David L, Maloyan A, Rugonyi S. Increased Hemodynamic Load in Early Embryonic Stages Alters Myofibril and Mitochondrial Organization in the Myocardium. Front Physiol 2017; 8:631. [PMID: 28912723 PMCID: PMC5582297 DOI: 10.3389/fphys.2017.00631] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/14/2017] [Indexed: 01/08/2023] Open
Abstract
Normal blood flow is essential for proper heart formation during embryonic development, as abnormal hemodynamic load (blood pressure and shear stress) results in cardiac defects seen in congenital heart disease (CHD). However, the detrimental remodeling processes that relate altered blood flow to cardiac malformation and defects remain unclear. Heart development is a finely orchestrated process with rapid transformations that occur at the tissue, cell, and subcellular levels. Myocardial cells play an essential role in cardiac tissue maturation by aligning in the direction of stretch and increasing the number of contractile units as hemodynamic load increases throughout development. This study elucidates the early effects of altered blood flow on myofibril and mitochondrial configuration in the outflow tract myocardium in vivo. Outflow tract banding was used to increase hemodynamic load in the chicken embryo heart between Hamburger and Hamilton stages 18 and 24 (~24 h during tubular heart stages). 3D focused ion beam scanning electron microscopy analysis determined that increased hemodynamic load induced changes in the developing myocardium, characterized by thicker myofibril bundles that were more disbursed in circumferential orientation, and mitochondria that organized in large clusters around the nucleus. Proteomic mass-spectrometry analysis quantified altered protein composition after banding that is consistent with altered myofibril thin filament assembly and function, and mitochondrial maintenance and organization. Additionally, pathway analysis of the proteomics data identified possible activation of signaling pathways in response to banding, including the renin-angiotensin system (RAS). Imaging and proteomic data combined indicate that myofibril and mitochondrial arrangement in early embryonic stages is a critical developmental process that when disturbed by altered blood flow may contribute to cardiac malformation and defects.
Collapse
Affiliation(s)
- Madeline Midgett
- Biomedical Engineering, Oregon Health & Science UniversityPortland, OR, United States
| | - Claudia S López
- Biomedical Engineering, Oregon Health & Science UniversityPortland, OR, United States.,Multiscale Microscopy Core, OHSU Center for Spatial Systems Biomedicine, Oregon Health & Science UniversityPortland, OR, United States
| | - Larry David
- Proteomics Core, Oregon Health & Science UniversityPortland, OR, United States
| | - Alina Maloyan
- Knight Cardiovascular Institute, Oregon Health & Science UniversityPortland, OR, United States
| | - Sandra Rugonyi
- Biomedical Engineering, Oregon Health & Science UniversityPortland, OR, United States
| |
Collapse
|
19
|
The influence of mitochondrial dynamics on mitochondrial genome stability. Curr Genet 2017; 64:199-214. [PMID: 28573336 DOI: 10.1007/s00294-017-0717-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Revised: 05/15/2017] [Accepted: 05/27/2017] [Indexed: 12/28/2022]
Abstract
Mitochondria are dynamic organelles that fuse and divide. These changes alter the number and distribution of mitochondrial structures throughout the cell in response to developmental and metabolic cues. We have demonstrated that mitochondrial fission is essential to the maintenance of mitochondrial DNA (mtDNA) under changing metabolic conditions in wild-type Saccharomyces cerevisiae. While increased loss of mtDNA integrity has been demonstrated for dnm1-∆ fission mutants after growth in a non-fermentable carbon source, we demonstrate that growth of yeast in different carbon sources affects the frequency of mtDNA loss, even when the carbon sources are fermentable. In addition, we demonstrate that the impact of fission on mtDNA maintenance during growth in different carbon sources is neither mediated by retrograde signaling nor mitophagy. Instead, we demonstrate that mitochondrial distribution and mtDNA maintenance phenotypes conferred by loss of Dnm1p are suppressed by the loss of Sod2p, the mitochondrial matrix superoxide dismutase.
Collapse
|
20
|
Wakim J, Goudenege D, Perrot R, Gueguen N, Desquiret-Dumas V, Chao de la Barca JM, Dalla Rosa I, Manero F, Le Mao M, Chupin S, Chevrollier A, Procaccio V, Bonneau D, Logan DC, Reynier P, Lenaers G, Khiati S. CLUH couples mitochondrial distribution to the energetic and metabolic status. J Cell Sci 2017; 130:1940-1951. [PMID: 28424233 DOI: 10.1242/jcs.201616] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/12/2017] [Indexed: 12/13/2022] Open
Abstract
Mitochondrial dynamics and distribution are critical for supplying ATP in response to energy demand. CLUH is a protein involved in mitochondrial distribution whose dysfunction leads to mitochondrial clustering, the metabolic consequences of which remain unknown. To gain insight into the role of CLUH on mitochondrial energy production and cellular metabolism, we have generated CLUH-knockout cells using CRISPR/Cas9. Mitochondrial clustering was associated with a smaller cell size and with decreased abundance of respiratory complexes, resulting in oxidative phosphorylation (OXPHOS) defects. This energetic impairment was found to be due to the alteration of mitochondrial translation and to a metabolic shift towards glucose dependency. Metabolomic profiling by mass spectroscopy revealed an increase in the concentration of some amino acids, indicating a dysfunctional Krebs cycle, and increased palmitoylcarnitine concentration, indicating an alteration of fatty acid oxidation, and a dramatic decrease in the concentrations of phosphatidylcholine and sphingomyeline, consistent with the decreased cell size. Taken together, our study establishes a clear function for CLUH in coupling mitochondrial distribution to the control of cell energetic and metabolic status.
Collapse
Affiliation(s)
- Jamal Wakim
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - David Goudenege
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Rodolphe Perrot
- SCIAM, Institut de Biologie en Sante, Université d'Angers, Angers 49933, France
| | - Naig Gueguen
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Valerie Desquiret-Dumas
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | | | | | - Florence Manero
- SCIAM, Institut de Biologie en Sante, Université d'Angers, Angers 49933, France
| | - Morgane Le Mao
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Stephanie Chupin
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Arnaud Chevrollier
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Vincent Procaccio
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Dominique Bonneau
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - David C Logan
- MitoStress team, IRHS, Université d'Angers, Agrocampus-Ouest, INRA, SFR QuaSaV, Beaucouzé 49071, France
| | - Pascal Reynier
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Guy Lenaers
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| | - Salim Khiati
- Equipe MitoLab, Institut MitoVasc, Université d'Angers, UMR CNRS 6015, INSERM U1083, Angers, 49933 France
| |
Collapse
|
21
|
Schatton D, Pla-Martin D, Marx MC, Hansen H, Mourier A, Nemazanyy I, Pessia A, Zentis P, Corona T, Kondylis V, Barth E, Schauss AC, Velagapudi V, Rugarli EI. CLUH regulates mitochondrial metabolism by controlling translation and decay of target mRNAs. J Cell Biol 2017; 216:675-693. [PMID: 28188211 PMCID: PMC5350512 DOI: 10.1083/jcb.201607019] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 12/06/2016] [Accepted: 01/06/2017] [Indexed: 12/21/2022] Open
Abstract
Mitochondria are essential organelles that host crucial metabolic pathways and produce adenosine triphosphate. The mitochondrial proteome is heterogeneous among tissues and can dynamically change in response to different metabolic conditions. Although the transcriptional programs that govern mitochondrial biogenesis and respiratory function are well known, posttranscriptional regulatory mechanisms remain unclear. In this study, we show that the cytosolic RNA-binding protein clustered mitochondria homologue (CLUH) regulates the expression of a mitochondrial protein network supporting key metabolic programs required under nutrient deprivation. CLUH exerts its function by controlling the stability and translation of target messenger RNAs. In the absence of Cluh, mitochondria are severely depleted of crucial enzymes involved in catabolic energy-converting pathways. CLUH preserves oxidative mitochondrial function and glucose homeostasis, thus preventing death at the fetal-neonatal transition. In the adult liver, CLUH ensures maximal respiration capacity and the metabolic response to starvation. Our results shed new light on the posttranscriptional mechanisms controlling the expression of mitochondrial proteins and suggest novel strategies to tailor mitochondrial function to physiological and pathological conditions.
Collapse
Affiliation(s)
- Désirée Schatton
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - David Pla-Martin
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Marie-Charlotte Marx
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Henriette Hansen
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Arnaud Mourier
- Department of Mitochondrial Biology, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Ivan Nemazanyy
- Paris Descartes University, Sorbonne Paris Cité, 75006 Paris, France
| | - Alberto Pessia
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, 00290 Helsinki, Finland
| | - Peter Zentis
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Teresa Corona
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Vangelis Kondylis
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Esther Barth
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Astrid C Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| | - Vidya Velagapudi
- Metabolomics Unit, Institute for Molecular Medicine Finland, University of Helsinki, 00290 Helsinki, Finland
| | - Elena I Rugarli
- Institute for Genetics, University of Cologne, 50674 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50931 Cologne, Germany
| |
Collapse
|
22
|
Wang ZH, Clark C, Geisbrecht ER. Drosophila clueless is involved in Parkin-dependent mitophagy by promoting VCP-mediated Marf degradation. Hum Mol Genet 2016; 25:1946-1964. [PMID: 26931463 PMCID: PMC5062585 DOI: 10.1093/hmg/ddw067] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 02/22/2016] [Indexed: 12/31/2022] Open
Abstract
PINK1/Parkin-mediated mitochondrial quality control (MQC) requires valosin-containing protein (VCP)-dependent Mitofusin/Marf degradation to prevent damaged organelles from fusing with the healthy mitochondrial pool, facilitating mitochondrial clearance by autophagy. Drosophila clueless (clu) was found to interact genetically with PINK1 and parkin to regulate mitochondrial clustering in germ cells. However, whether Clu acts in MQC has not been investigated. Here, we show that overexpression of Drosophila Clu complements PINK1, but not parkin, mutant muscles. Loss of clu leads to the recruitment of Parkin, VCP/p97, p62/Ref(2)P and Atg8a to depolarized swollen mitochondria. However, clearance of damaged mitochondria is impeded. This paradox is resolved by the findings that excessive mitochondrial fission or inhibition of fusion alleviates mitochondrial defects and impaired mitophagy caused by clu depletion. Furthermore, Clu is upstream of and binds to VCP in vivo and promotes VCP-dependent Marf degradation in vitro Marf accumulates in whole muscle lysates of clu-deficient flies and is destabilized upon Clu overexpression. Thus, Clu is essential for mitochondrial homeostasis and functions in concert with Parkin and VCP for Marf degradation to promote damaged mitochondrial clearance.
Collapse
Affiliation(s)
- Zong-Heng Wang
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, MO 64110, USA and
| | - Cheryl Clark
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Erika R Geisbrecht
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, MO 64110, USA and Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| |
Collapse
|
23
|
Edgcomb VP, Pachiadaki MG, Mara P, Kormas KA, Leadbetter ER, Bernhard JM. Gene expression profiling of microbial activities and interactions in sediments under haloclines of E. Mediterranean deep hypersaline anoxic basins. ISME JOURNAL 2016; 10:2643-2657. [PMID: 27093045 DOI: 10.1038/ismej.2016.58] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/11/2016] [Accepted: 03/03/2016] [Indexed: 11/09/2022]
Abstract
Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most polyextreme habitats on Earth. In comparison to microbial activities occurring within the haloclines and brines of these unusual water column habitats near the Mediterranean seafloor, relatively little is known about microbial metabolic activities in the underlying sediments. In addition, it is not known whether activities are shaped by the unique chemistries of the different DHAB brines and whether evidence exists for active microbial eukaryotes in those sediments. Metatranscriptome analysis was applied to sediment samples collected using ROV Jason from underneath the haloclines of Urania, Discovery and L'Atalante DHABs and a control site. We report on expression of genes associated with sulfur and nitrogen cycling, putative osmolyte biosynthetic pathways and ion transporters, trace metal detoxification, selected eukaryotic activities (particularly of fungi), microbe-microbe interactions, and motility in sediments underlying the haloclines of three DHABs. Relative to our control sediment sample collected outside of Urania Basin, microbial communities (including eukaryotes) in the Urania and Discovery DHAB sediments showed upregulation of expressed genes associated with nitrogen transformations, osmolyte biosynthesis, heavy metals resistance and metabolism, eukaryotic organelle functions, and cell-cell interactions. Sediments underlying DHAB haloclines that have cumulative physico-chemical stressors within the limits of tolerance for microoorganisms can therefore be hotspots of activity in the deep Mediterranean Sea.
Collapse
Affiliation(s)
- Virginia P Edgcomb
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Maria G Pachiadaki
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Paraskevi Mara
- Department of Chemistry, University of Crete, Heraklion, Greece
| | - Konstantinos A Kormas
- Department of Ichthyology & Aquatic Environment, University of Thessaly, Volos, Greece
| | - Edward R Leadbetter
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Joan M Bernhard
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| |
Collapse
|
24
|
Woods LC, Berbusse GW, Naylor K. Microtubules Are Essential for Mitochondrial Dynamics-Fission, Fusion, and Motility-in Dictyostelium discoideum. Front Cell Dev Biol 2016; 4:19. [PMID: 27047941 PMCID: PMC4801864 DOI: 10.3389/fcell.2016.00019] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/03/2016] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial function is dependent upon mitochondrial structure which is in turn dependent upon mitochondrial dynamics, including fission, fusion, and motility. Here we examined the relationship between mitochondrial dynamics and the cytoskeleton in Dictyostelium discoideum. Using time-lapse analysis, we quantified mitochondrial fission, fusion, and motility in the presence of cytoskeleton disrupting pharmaceuticals and the absence of the potential mitochondria-cytoskeleton linker protein, CluA. Our results indicate that microtubules are essential for mitochondrial movement, as well as fission and fusion; actin plays a less significant role, perhaps selecting the mitochondria for transport. We also suggest that CluA is not a linker protein but plays an unidentified role in mitochondrial fission and fusion. The significance of our work is to gain further insight into the role the cytoskeleton plays in mitochondrial dynamics and function. By better understanding these processes we can better appreciate the underlying mitochondrial contributions to many neurological disorders characterized by altered mitochondrial dynamics, structure, and/or function.
Collapse
Affiliation(s)
- Laken C. Woods
- Department of Biology, University of Central ArkansasConway, AR, USA
| | - Gregory W. Berbusse
- Interdisciplinary Biomedical Sciences, University of Arkansas for Medical SciencesLittle Rock, AR, USA
| | - Kari Naylor
- Department of Biology, University of Central ArkansasConway, AR, USA
| |
Collapse
|
25
|
Sunter JD, Benz C, Andre J, Whipple S, McKean PG, Gull K, Ginger ML, Lukeš J. Modulation of flagellum attachment zone protein FLAM3 and regulation of the cell shape in Trypanosoma brucei life cycle transitions. J Cell Sci 2015; 128:3117-30. [PMID: 26148511 PMCID: PMC4541047 DOI: 10.1242/jcs.171645] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/29/2015] [Indexed: 11/25/2022] Open
Abstract
The cell shape of Trypanosoma brucei is influenced by flagellum-to-cell-body attachment through a specialised structure – the flagellum attachment zone (FAZ). T. brucei exhibits numerous morphological forms during its life cycle and, at each stage, the FAZ length varies. We have analysed FLAM3, a large protein that localises to the FAZ region within the old and new flagellum. Ablation of FLAM3 expression causes a reduction in FAZ length; however, this has remarkably different consequences in the tsetse procyclic form versus the mammalian bloodstream form. In procyclic form cells FLAM3 RNAi results in the transition to an epimastigote-like shape, whereas in bloodstream form cells a severe cytokinesis defect associated with flagellum detachment is observed. Moreover, we demonstrate that the amount of FLAM3 and its localisation is dependent on ClpGM6 expression and vice versa. This evidence demonstrates that FAZ is a key regulator of trypanosome shape, with experimental perturbations being life cycle form dependent. An evolutionary cell biology explanation suggests that these differences are a reflection of the division process, the cytoskeleton and intrinsic structural plasticity of particular life cycle forms. Summary:Trypanosoma brucei FLAM3 is a flagellar FAZ protein. Its depletion leads to a reduction in FAZ length, which has different consequences depending on the life cycle stage of the parasite.
Collapse
Affiliation(s)
- Jack D Sunter
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Corinna Benz
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis) 37005, Czech Republic
| | - Jane Andre
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Sarah Whipple
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Paul G McKean
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Michael L Ginger
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Julius Lukeš
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis) 37005, Czech Republic Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis) 37005, Czech Republic Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
| |
Collapse
|
26
|
Wang ZH, Rabouille C, Geisbrecht ER. Loss of a Clueless-dGRASP complex results in ER stress and blocks Integrin exit from the perinuclear endoplasmic reticulum in Drosophila larval muscle. Biol Open 2015; 4:636-48. [PMID: 25862246 PMCID: PMC4434815 DOI: 10.1242/bio.201511551] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Drosophila Clueless (Clu) and its conserved orthologs are known for their role in the prevention of mitochondrial clustering. Here, we uncover a new role for Clu in the delivery of integrin subunits in muscle tissue. In clu mutants, αPS2 integrin, but not βPS integrin, abnormally accumulates in a perinuclear endoplasmic reticulum (ER) subdomain, a site that mirrors the endogenous localization of Clu. Loss of components essential for mitochondrial distribution do not phenocopy the clu mutant αPS2 phenotype. Conversely, RNAi knockdown of the DrosophilaGolgi reassembly and stacking protein GRASP55/65 (dGRASP) recapitulates clu defects, including the abnormal accumulation of αPS2 and larval locomotor activity. Both Clu and dGRASP proteins physically interact and loss of Clu displaces dGRASP from ER exit sites, suggesting that Clu cooperates with dGRASP for the exit of αPS2 from a perinuclear subdomain in the ER. We also found that Clu and dGRASP loss of function leads to ER stress and that the stability of the ER exit site protein Sec16 is severely compromised in the clu mutants, thus explaining the ER accumulation of αPS2. Remarkably, exposure of clu RNAi larvae to chemical chaperones restores both αPS2 delivery and functional ER exit sites. We propose that Clu together with dGRASP prevents ER stress and therefore maintains Sec16 stability essential for the functional organization of perinuclear early secretory pathway. This, in turn, is essential for integrin subunit αPS2 ER exit in Drosophila larval myofibers.
Collapse
Affiliation(s)
- Zong-Heng Wang
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, MO 64110, USA
| | - Catherine Rabouille
- Hubrecht Institute-KNAW & University Medical Center Utrecht, 3584 CT Utrecht, The Netherlands The Department of Cell Biology, UMC Utrecht, 3584 CX Utrecht, The Netherlands
| | - Erika R Geisbrecht
- Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri, Kansas City, MO 64110, USA Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| |
Collapse
|
27
|
Gao J, Schatton D, Martinelli P, Hansen H, Pla-Martin D, Barth E, Becker C, Altmueller J, Frommolt P, Sardiello M, Rugarli EI. CLUH regulates mitochondrial biogenesis by binding mRNAs of nuclear-encoded mitochondrial proteins. ACTA ACUST UNITED AC 2015; 207:213-23. [PMID: 25349259 PMCID: PMC4210445 DOI: 10.1083/jcb.201403129] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
CLUH is a cytosolic mRNA-binding protein that specifically binds a subset of mRNAs encoding mitochondrial proteins and may regulate their localized translation. Mitochondrial function requires coordination of two genomes for protein biogenesis, efficient quality control mechanisms, and appropriate distribution of the organelles within the cell. How these mechanisms are integrated is currently not understood. Loss of the Clu1/CluA homologue (CLUH) gene led to clustering of the mitochondrial network by an unknown mechanism. We find that CLUH is coregulated both with genes encoding mitochondrial proteins and with genes involved in ribosomal biogenesis and translation. Our functional analysis identifies CLUH as a cytosolic messenger ribonucleic acid (RNA; mRNA)–binding protein. RNA immunoprecipitation experiments followed by next-generation sequencing demonstrated that CLUH specifically binds a subset of mRNAs encoding mitochondrial proteins. CLUH depletion decreased the levels of proteins translated by target transcripts and caused mitochondrial clustering. A fraction of CLUH colocalizes with tyrosinated tubulin and can be detected close to mitochondria, suggesting a role in regulating transport or translation of target transcripts close to mitochondria. Our data unravel a novel mechanism linking mitochondrial biogenesis and distribution.
Collapse
Affiliation(s)
- Jie Gao
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Désirée Schatton
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Paola Martinelli
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Henriette Hansen
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - David Pla-Martin
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Esther Barth
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Christian Becker
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Janine Altmueller
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Peter Frommolt
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| | - Marco Sardiello
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030 Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX 77030
| | - Elena I Rugarli
- Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany Institute for Genetics, Center for Molecular Medicine, Cologne Center for Genomics, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, University of Cologne, 50923 Cologne, Germany
| |
Collapse
|
28
|
Annesley SJ, Chen S, Francione LM, Sanislav O, Chavan AJ, Farah C, De Piazza SW, Storey CL, Ilievska J, Fernando SG, Smith PK, Lay ST, Fisher PR. Dictyostelium, a microbial model for brain disease. Biochim Biophys Acta Gen Subj 2013; 1840:1413-32. [PMID: 24161926 DOI: 10.1016/j.bbagen.2013.10.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 10/05/2013] [Accepted: 10/10/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND Most neurodegenerative diseases are associated with mitochondrial dysfunction. In humans, mutations in mitochondrial genes result in a range of phenotypic outcomes which do not correlate well with the underlying genetic cause. Other neurodegenerative diseases are caused by mutations that affect the function and trafficking of lysosomes, endosomes and autophagosomes. Many of the complexities of these human diseases can be avoided by studying them in the simple eukaryotic model Dictyostelium discoideum. SCOPE OF REVIEW This review describes research using Dictyostelium to study cytopathological pathways underlying a variety of neurodegenerative diseases including mitochondrial, lysosomal and vesicle trafficking disorders. MAJOR CONCLUSIONS Generalised mitochondrial respiratory deficiencies in Dictyostelium produce a consistent pattern of defective phenotypes that are caused by chronic activation of a cellular energy sensor AMPK (AMP-activated protein kinase) and not ATP deficiency per se. Surprisingly, when individual subunits of Complex I are knocked out, both AMPK-dependent and AMPK-independent, subunit-specific phenotypes are observed. Many nonmitochondrial proteins associated with neurological disorders have homologues in Dictyostelium and are associated with the function and trafficking of lysosomes and endosomes. Conversely, some genes associated with neurodegenerative disorders do not have homologues in Dictyostelium and this provides a unique avenue for studying these mutated proteins in the absence of endogeneous protein. GENERAL SIGNIFICANCE Using the Dictyostelium model we have gained insights into the sublethal cytopathological pathways whose dysregulation contributes to phenotypic outcomes in neurodegenerative disease. This work is beginning to distinguish correlation, cause and effect in the complex network of cross talk between the various organelles involved. This article is part of a Special Issue entitled Frontiers of Mitochondrial Research.
Collapse
Affiliation(s)
- S J Annesley
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - S Chen
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - L M Francione
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - O Sanislav
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - A J Chavan
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - C Farah
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - S W De Piazza
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - C L Storey
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - J Ilievska
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - S G Fernando
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - P K Smith
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - S T Lay
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086
| | - P R Fisher
- Department of Microbiology, La Trobe University, Plenty Rd., Bundoora, VIC, Australia, 3086.
| |
Collapse
|
29
|
Abstract
SIGNIFICANCE For a plant to grow and develop, energy and appropriate building blocks are a fundamental requirement. Mitochondrial respiration is a vital source for both. The delicate redox processes that make up respiration are affected by the plant's changing environment. Therefore, mitochondrial regulation is critically important to maintain cellular homeostasis. This involves sensing signals from changes in mitochondrial physiology, transducing this information, and mounting tailored responses, by either adjusting mitochondrial and cellular functions directly or reprogramming gene expression. RECENT ADVANCES Retrograde (RTG) signaling, by which mitochondrial signals control nuclear gene expression, has been a field of very active research in recent years. Nevertheless, no mitochondrial RTG-signaling pathway is yet understood in plants. This review summarizes recent advances toward elucidating redox processes and other bioenergetic factors as a part of RTG signaling of plant mitochondria. CRITICAL ISSUES Novel insights into mitochondrial physiology and redox-regulation provide a framework of upstream signaling. On the other end, downstream responses to modified mitochondrial function have become available, including transcriptomic data and mitochondrial phenotypes, revealing processes in the plant that are under mitochondrial control. FUTURE DIRECTIONS Drawing parallels to chloroplast signaling and mitochondrial signaling in animal systems allows to bridge gaps in the current understanding and to deduce promising directions for future research. It is proposed that targeted usage of new technical approaches, such as quantitative in vivo imaging, will provide novel leverage to the dissection of plant mitochondrial signaling.
Collapse
|
30
|
Sen A, Damm VT, Cox RT. Drosophila clueless is highly expressed in larval neuroblasts, affects mitochondrial localization and suppresses mitochondrial oxidative damage. PLoS One 2013; 8:e54283. [PMID: 23342118 PMCID: PMC3547001 DOI: 10.1371/journal.pone.0054283] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/11/2012] [Indexed: 12/26/2022] Open
Abstract
Mitochondria are critical for neuronal function due to the high demand of ATP in these cell types. During Drosophila development, neuroblasts in the larval brain divide asymmetrically to populate the adult central nervous system. While many of the proteins responsible for maintaining neuroblast cell fate and asymmetric cell divisions are known, little is know about the role of metabolism and mitochondria in neuroblast division and maintenance. The gene clueless (clu) has been previously shown to be important for mitochondrial function. clu mutant adults have severely shortened lifespans and are highly uncoordinated. Part of their lack of coordination is due to defects in muscle, however, in this study we have identified high levels of Clu expression in larval neuroblasts and other regions of the dividing larval brain. We show while mitochondria in clu mutant neuroblasts are mislocalized during the cell cycle, surprisingly, overall brain morphology appears to be normal. This is explained by our observation that clu mutant larvae have normal levels of ATP and do not suffer oxidative damage, in sharp contrast to clu mutant adults. Mutations in two other genes encoding mitochondrial proteins, technical knockout and stress sensitive B, do not cause neuroblast mitochondrial mislocalization, even though technical knockout mutant larvae suffer oxidative damage. These results suggest Clu functions upstream of electron transport and oxidative phosphorylation, has a role in suppressing oxidative damage in the cell, and that lack of Clu's specific function causes mitochondria to mislocalize. These results also support the previous observation that larval development relies on aerobic glycolysis, rather than oxidative phosphorylation. Thus Clu's role in mitochondrial function is not critical during larval development, but is important for pupae and adults.
Collapse
Affiliation(s)
- Aditya Sen
- Department of Biochemistry and Molecular Biology, Uniformed Services University, Bethesda, Maryland, United States of America
| | | | | |
Collapse
|
31
|
Schimmel BG, Berbusse GW, Naylor K. Mitochondrial fission and fusion in Dictyostelium discoideum: a search for proteins involved in membrane dynamics. BMC Res Notes 2012; 5:505. [PMID: 22980139 PMCID: PMC3492061 DOI: 10.1186/1756-0500-5-505] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Accepted: 09/06/2012] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Mitochondrial morphology is maintained by two distinct membrane events -fission and fusion. Altering these conserved processes can disrupt mitochondrial morphology and distribution, thereby disrupting the organelle's functionality and impeding cellular function. In higher eukaryotes, these processes are mediated by a family of dynamin-related proteins (DRP's). In the lower eukaryotes, for instance Dictyostelium discoideum, mitochondrial fission and fusion have been implicated but not yet established. To understand the overall mechanism of these dynamics across organisms, we developed an assay to identify fission and fusion events in Dictyostelium and to assess the involvement of the mitochondrial proteins, MidA, CluA, and two DRP's, DymA and DymB. FINDINGS Using laser scanning confocal microscopy we show, for the first time, that lower eukaryotes mediate mitochondrial fission and fusion. In Dictyostelium, these processes are balanced, occurring approximately 1 event/minute. Quantification of the rates in midA-, cluA-, dymA-, or dymB- strains established that MidA appears to play an indirect role in the regulation of fission and fusion, while the DRP's are not essential for these processes. Rates of fission and fusion were significantly reduced in cluA-cells, indicating that CluA is necessary for maintaining both fission and fusion. CONCLUSIONS We have successfully demonstrated that Dictyostelium mitochondria undergo the dynamic processes of fission and fusion. The classical mediators of membrane dynamics - the DRP's - are not necessary for these dynamics, whereas CluA is necessary for both processes. This work contributes to our overall understanding of mitochondrial dynamics and ultimately will provide additional insight into mitochondrial disease.
Collapse
Affiliation(s)
- Brixey G Schimmel
- Biology Department, University of Central Arkansas, Conway, AR 72035, USA
| | | | | |
Collapse
|
32
|
Amarnath S, Kawli T, Mohanty S, Srinivasan N, Nanjundiah V. Pleiotropic roles of a ribosomal protein in Dictyostelium discoideum. PLoS One 2012; 7:e30644. [PMID: 22363460 PMCID: PMC3281849 DOI: 10.1371/journal.pone.0030644] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Accepted: 12/20/2011] [Indexed: 11/22/2022] Open
Abstract
The cell cycle phase at starvation influences post-starvation differentiation and morphogenesis in Dictyostelium discoideum. We found that when expressed in Saccharomyces cerevisiae, a D. discoideum cDNA that encodes the ribosomal protein S4 (DdS4) rescues mutations in the cell cycle genes cdc24, cdc42 and bem1. The products of these genes affect morphogenesis in yeast via a coordinated moulding of the cytoskeleton during bud site selection. D. discoideum cells that over- or under-expressed DdS4 did not show detectable changes in protein synthesis but displayed similar developmental aberrations whose intensity was graded with the extent of over- or under-expression. This suggested that DdS4 might influence morphogenesis via a stoichiometric effect – specifically, by taking part in a multimeric complex similar to the one involving Cdc24p, Cdc42p and Bem1p in yeast. In support of the hypothesis, the S. cerevisiae proteins Cdc24p, Cdc42p and Bem1p as well as their D. discoideum cognates could be co-precipitated with antibodies to DdS4. Computational analysis and mutational studies explained these findings: a C-terminal domain of DdS4 is the functional equivalent of an SH3 domain in the yeast scaffold protein Bem1p that is central to constructing the bud site selection complex. Thus in addition to being part of the ribosome, DdS4 has a second function, also as part of a multi-protein complex. We speculate that the existence of the second role can act as a safeguard against perturbations to ribosome function caused by spontaneous variations in DdS4 levels.
Collapse
Affiliation(s)
- Smita Amarnath
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.
| | | | | | | | | |
Collapse
|
33
|
Sugden C, Ross S, Annesley SJ, Cole C, Bloomfield G, Ivens A, Skelton J, Fisher PR, Barton G, Williams JG. A Dictyostelium SH2 adaptor protein required for correct DIF-1 signaling and pattern formation. Dev Biol 2011; 353:290-301. [PMID: 21396932 PMCID: PMC3085826 DOI: 10.1016/j.ydbio.2011.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 02/28/2011] [Accepted: 03/02/2011] [Indexed: 11/25/2022]
Abstract
Dictyostelium is the only non-metazoan with functionally analyzed SH2 domains and studying them can give insights into their evolution and wider potential. LrrB has a novel domain configuration with leucine-rich repeat, 14-3-3 and SH2 protein–protein interaction modules. It is required for the correct expression of several specific genes in early development and here we characterize its role in later, multicellular development. During development in the light, slug formation in LrrB null (lrrB-) mutants is delayed relative to the parental strain, and the slugs are highly defective in phototaxis and thermotaxis. In the dark the mutant arrests development as an elongated mound, in a hitherto unreported process we term dark stalling. The developmental and phototaxis defects are cell autonomous and marker analysis shows that the pstO prestalk sub-region of the slug is aberrant in the lrrB- mutant. Expression profiling, by parallel micro-array and deep RNA sequence analyses, reveals many other alterations in prestalk-specific gene expression in lrrB- slugs, including reduced expression of the ecmB gene and elevated expression of ampA. During culmination ampA is ectopically expressed in the stalk, there is no expression of ampA and ecmB in the lower cup and the mutant fruiting bodies lack a basal disc. The basal disc cup derives from the pstB cells and this population is greatly reduced in the lrrB- mutant. This anatomical feature is a hallmark of mutants aberrant in signaling by DIF-1, the polyketide that induces prestalk and stalk cell differentiation. In a DIF-1 induction assay the lrrB- mutant is profoundly defective in ecmB activation but only marginally defective in ecmA induction. Thus the mutation partially uncouples these two inductive events. In early development LrrB interacts physically and functionally with CldA, another SH2 domain containing protein. However, the CldA null mutant does not phenocopy the lrrB- in its aberrant multicellular development or phototaxis defect, implying that the early and late functions of LrrB are affected in different ways. These observations, coupled with its domain structure, suggest that LrrB is an SH2 adaptor protein active in diverse developmental signaling pathways.
Collapse
Affiliation(s)
- Christopher Sugden
- School of Life Sciences, University of Dundee, Dow St., Dundee, DD1 5EH, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Dynamic Behavior of Double-Membrane-Bounded Organelles in Plant Cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2011; 286:181-222. [DOI: 10.1016/b978-0-12-385859-7.00004-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
35
|
Francione LM, Annesley SJ, Carilla-Latorre S, Escalante R, Fisher PR. The Dictyostelium model for mitochondrial disease. Semin Cell Dev Biol 2010; 22:120-30. [PMID: 21129494 DOI: 10.1016/j.semcdb.2010.11.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 11/19/2010] [Accepted: 11/24/2010] [Indexed: 12/31/2022]
Abstract
Mitochondrial diseases are a diverse family of genetic disorders caused by mutations affecting mitochondrial proteins encoded in either the nuclear or the mitochondrial genome. By impairing mitochondrial oxidative phosphorylation, they compromise cellular energy production and the downstream consequences in humans are a bewilderingly complex array of signs and symptoms that can affect any of the major organ systems in unpredictable combinations. This complexity and unpredictability has limited our understanding of the cytopathological consequences of mitochondrial dysfunction. By contrast, in Dictyostelium the mitochondrial disease phenotypes are consistent, measurable "readouts" of dysregulated intracellular signalling pathways. When the underlying genetic defects would produce coordinate, generalized deficiencies in multiple mitochondrial respiratory complexes, the disease phenotypes are mediated by chronic activation of an energy-sensing protein kinase, AMP-activated protein kinase (AMPK). This chronic AMPK hyperactivity maintains mitochondrial mass and cellular ATP concentrations at normal levels, but chronically impairs growth, cell cycle progression, multicellular development, photosensory and thermosensory signal transduction. It also causes the cells to support greater proliferation of the intracellular bacterial pathogen, Legionella pneumophila. Notably however, phagocytic and macropinocytic nutrient uptake are impervious both to AMPK signalling and to these types of mitochondrial dysfunction. Surprisingly, a Complex I-specific deficiency (midA knockout) not only causes the foregoing AMPK-mediated defects, but also produces a dramatic deficit in endocytic nutrient uptake accompanied by an additional secondary defect in growth. More restricted and specific phenotypic outcomes are produced by knocking out genes for nuclear-encoded mitochondrial proteins that are not required for respiration. The Dictyostelium model for mitochondrial disease has thus revealed consistent patterns of sublethal dysregulation of intracellular signalling pathways that are produced by different types of underlying mitochondrial dysfunction.
Collapse
|
36
|
Moulder GL, Cremona GH, Duerr J, Stirman JN, Fields SD, Martin W, Qadota H, Benian GM, Lu H, Barstead RJ. α-actinin is required for the proper assembly of Z-disk/focal-adhesion-like structures and for efficient locomotion in Caenorhabditis elegans. J Mol Biol 2010; 403:516-28. [PMID: 20850453 PMCID: PMC3440862 DOI: 10.1016/j.jmb.2010.08.055] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Revised: 08/10/2010] [Accepted: 08/30/2010] [Indexed: 11/22/2022]
Abstract
The actin binding protein α-actinin is a major component of focal adhesions found in vertebrate cells and of focal-adhesion-like structures found in the body wall muscle of the nematode Caenorhabditis elegans. To study its in vivo function in this genetic model system, we isolated a strain carrying a deletion of the single C. elegans α-actinin gene. We assessed the cytological organization of other C. elegans focal adhesion proteins and the ultrastructure of the mutant. The mutant does not have normal dense bodies, as observed by electron microscopy; however, these dense-body-like structures still contain the focal adhesion proteins integrin, talin, and vinculin, as observed by immunofluorescence microscopy. Actin is found in normal-appearing I-bands, but with abnormal accumulations near muscle cell membranes. Although swimming in water appeared grossly normal, use of automated methods for tracking the locomotion of individual worms revealed a defect in bending. We propose that the reduced motility of α-actinin null is due to abnormal dense bodies that are less able to transmit the forces generated by actin/myosin interactions.
Collapse
Affiliation(s)
- Gary L. Moulder
- Department of Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Gina H. Cremona
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100
| | - Janet Duerr
- Department of Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Jeffrey N. Stirman
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100
| | - Stephen D. Fields
- Department of Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Wendy Martin
- Department of Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Hiroshi Qadota
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Guy M. Benian
- Department of Pathology, Emory University, Atlanta, Georgia 30322
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100
| | - Robert J. Barstead
- Department of Molecular and Cell Biology, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| |
Collapse
|
37
|
Abstract
Mitochondria are involved in many fundamental processes underpinning plant growth, development and death. Owing to their multiple roles, as the sites of the tricarboxylic acid cycle and oxidative phosphorylation, as harbourers of their own genomes and as sensors of cell redox status, amongst others, mitochondria are in a unique position to act as sentinels of cell physiology. The plant chondriome is typically organized as a population of physically discrete organelles, but visualization of mitochondria in living tissues has shown that the mitochondrial population is highly interactive. Mitochondria are highly motile and movement on the cytoskeleton ensures that the physically discrete organelles come into contact with one another, which allows transient fusion, followed by division of the mitochondrial membranes. This article serves to review our current knowledge of mitochondrial fusion and division, and link this to recent discoveries regarding a putative mitochondrial 'health-check' and repair process, whereby non-repairable dysfunctional mitochondria can be removed from the chondriome. It is proposed that the unequal distribution of the multipartite plant mitochondrial genome between discrete organelles provides the driver for transient mitochondrial fusion that, in turn, is dependent on mitochondrial motility, and that both fusion and motility are necessary to maintain a healthy functional chondriome.
Collapse
|
38
|
Sugden C, Ross S, Bloomfield G, Ivens A, Skelton J, Mueller-Taubenberger A, Williams JG. Two novel Src homology 2 domain proteins interact to regulate dictyostelium gene expression during growth and early development. J Biol Chem 2010; 285:22927-35. [PMID: 20457612 PMCID: PMC2906285 DOI: 10.1074/jbc.m110.139733] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Indexed: 01/01/2023] Open
Abstract
There are 13 Dictyostelium Src homology 2 (SH2) domain proteins, almost 10-fold fewer than in mammals, and only three are functionally unassigned. One of these, LrrB, contains a novel combination of protein interaction domains: an SH2 domain and a leucine-rich repeat domain. Growth and early development appear normal in the mutant, but expression profiling reveals that three genes active at these stages are greatly underexpressed: the ttdA metallohydrolase, the abcG10 small molecule transporter, and the cinB esterase. In contrast, the multigene family encoding the lectin discoidin 1 is overexpressed in the disruptant strain. LrrB binds to 14-3-3 protein, and the level of binding is highest during growth and decreases during early development. Comparative tandem affinity purification tagging shows that LrrB also interacts, via its SH2 domain and in a tyrosine phosphorylation-dependent manner, with two novel proteins: CldA and CldB. Both of these proteins contain a Clu domain, a >200-amino acid sequence present within highly conserved eukaryotic proteins required for correct mitochondrial dispersal. A functional interaction of LrrB with CldA is supported by the fact that a cldA disruptant mutant also underexpresses ttdA, abcG10, and cinB. Significantly, CldA is itself one of the three functionally unassigned SH2 domain proteins. Thus, just as in metazoa, but on a vastly reduced numerical scale, an interacting network of SH2 domain proteins regulates specific Dictyostelium gene expression.
Collapse
Affiliation(s)
- Christopher Sugden
- From the
School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom
| | - Susan Ross
- From the
School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom
| | - Gareth Bloomfield
- the
Wellcome Trust Sanger Institute, Hinxton CB10 1SA, United Kingdom
| | - Alasdair Ivens
- the
Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom, and
| | - Jason Skelton
- the
Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom, and
| | - Annette Mueller-Taubenberger
- the
Institute for Cell Biology and Center for Integrated Protein Science, Munich, Ludwig Maximilians University, Schillerstrasse 42, D-80336 Munich, Germany
| | - Jeffrey G. Williams
- From the
School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland, United Kingdom
| |
Collapse
|
39
|
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.
Collapse
Affiliation(s)
- Jürgen Bereiter-Hahn
- Center of Excellence Macromolecular Complexes, Institute for Cell Biology and Neurosciences, Goethe University, Frankfurt am Main, Germany
| | | |
Collapse
|
40
|
Cox RT, Spradling AC. Clueless, a conserved Drosophila gene required for mitochondrial subcellular localization, interacts genetically with parkin. Dis Model Mech 2009; 2:490-9. [PMID: 19638420 PMCID: PMC2737057 DOI: 10.1242/dmm.002378] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Parkinson's disease has been linked to altered mitochondrial function. Mutations in parkin (park), the Drosophila ortholog of a human gene that is responsible for many familial cases of Parkinson's disease, shorten life span, abolish fertility and disrupt mitochondrial structure. However, the role played by Park in mitochondrial function remains unclear. Here, we describe a novel Drosophila gene, clueless (clu), which encodes a highly conserved tetratricopeptide repeat protein that is related closely to the CluA protein of Dictyostelium, Clu1 of Saccharomyces cerevisiae and to similar proteins in diverse metazoan eukaryotes from Arabidopsis to humans. Like its orthologs, loss of Drosophila clu causes mitochondria to cluster within cells. We find that strong clu mutations resemble park mutations in their effects on mitochondrial function and that the two genes interact genetically. Conversely, mitochondria in park homozygotes become highly clustered. We propose that Clu functions in a novel pathway that positions mitochondria within the cell based on their physiological state. Disruption of the Clu pathway may enhance oxidative damage, alter gene expression, cause mitochondria to cluster at microtubule plus ends, and lead eventually to mitochondrial failure.
Collapse
Affiliation(s)
- Rachel T Cox
- Department of Embryology/Howard Hughes Medical Institute, Carnegie Institution, 3520 San Martin Drive, Baltimore, MD 21218, USA
| | | |
Collapse
|
41
|
Barth C, Le P, Fisher PR. Mitochondrial biology and disease in Dictyostelium. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 263:207-52. [PMID: 17725968 DOI: 10.1016/s0074-7696(07)63005-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The cellular slime mold Dictyostelium discoideum has become an increasingly useful model for the study of mitochondrial biology and disease. Dictyostelium is an amoebazoan, a sister clade to the animal and fungal lineages. The mitochondrial biology of Dictyostelium exhibits some features which are unique, others which are common to all eukaryotes, and still others that are otherwise found only in the plant or the animal lineages. The AT-rich mitochondrial genome of Dictyostelium is larger than its mammalian counterpart and contains 56kb (compared to 17kb in mammals) encoding tRNAs, rRNAs, and 33 polypeptides (compared to 13 in mammals). It produces a single primary transcript that is cotranscriptionally processed into multiple monocistronic, dicistronic, and tricistronic mRNAs, tRNAs, and rRNAs. The mitochondrial fission mechanism employed by Dictyostelium involves both the extramitochondrial dynamin-based system used by plant, animal, and fungal mitochondria and the ancient FtsZ-based intramitochondrial fission process inherited from the bacterial ancestor. The mitochondrial protein-import apparatus is homologous to that of other eukaryote, and mitochondria in Dictyostelium play an important role in the programmed cell death pathways. Mitochondrial disease in Dictyostelium has been created both by targeted gene disruptions and by antisense RNA and RNAi inhibition of expression of essential nucleus-encoded mitochondrial proteins. This has revealed a regular pattern of aberrant mitochondrial disease phenotypes caused not by ATP insufficiency per se, but by chronic activation of the universal eukaryotic energy-sensing protein kinase AMPK. This novel insight into the cytopathological mechanisms of mitochondrial dysfunction suggests new possibilities for therapeutic intervention in mitochondrial and neurodegenerative diseases.
Collapse
Affiliation(s)
- Christian Barth
- Department of Microbiology, La Trobe University, Melbourne VIC 3086, Australia
| | | | | |
Collapse
|
42
|
Logan DC. Plant mitochondrial dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:430-41. [PMID: 16545471 DOI: 10.1016/j.bbamcr.2006.01.003] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2005] [Revised: 12/23/2005] [Accepted: 01/10/2006] [Indexed: 01/05/2023]
Abstract
Higher plant mitochondria are dynamic, pleomorphic organelles. The higher plant chondriome (all mitochondria in a cell collectively) is typically composed of numerous, physically discrete, mitochondria. However, frequent inter-mitochondrial fusion, enabling the mixing and recombination of mtDNA, ensures that the higher plant chondriome functions, at least genetically, as a discontinuous whole. Nothing is known about the genes controlling mitochondrial fusion in plants; there are no plant homologues of most of the genes known to be involved in fusion in other organisms. In contrast, the mitochondrial fission apparatus is generally conserved. Higher plant mitochondria use dynamin-like and Fis-type proteins for division; like yeast and animals, higher plants have lost the mitochondrial-specific form of the prokaryote-derived protein, FtsZ. In addition to being providers of energy for life, mitochondria provide a trigger for death. The role of mitochondrial dynamics in the initiation and promulgation of cell death is conserved in higher plants although there are specific differences in the genes and mechanisms involved relative to other higher eukaryotes.
Collapse
Affiliation(s)
- David C Logan
- School of Biology, Sir Harold Mitchell Building, University of St. Andrews, St Andrews, Fife, KY16 9TH Scotland, UK.
| |
Collapse
|
43
|
Kiefel BR, Gilson PR, Beech PL. Cell biology of mitochondrial dynamics. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 254:151-213. [PMID: 17147999 DOI: 10.1016/s0074-7696(06)54004-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mitochondria are the product of an ancient endosymbiotic event between an alpha-proteobacterium and an archael host. An early barrier to overcome in this relationship was the control of the bacterium's proliferation within the host. Undoubtedly, the bacterium (or protomitochondrion) would have used its own cell division apparatus to divide at first and, today a remnant of this system remains in some "ancient" and diverse eukaryotes such as algae and amoebae, the most conserved and widespread of all bacterial division proteins, FtsZ. In many of the eukaryotes that still use FtsZ to constrict the mitochondria from the inside, the mitochondria still resemble bacteria in shape and size. Eukaryotes, however, have a mitochondrial morphology that is often highly fluid, and in their tubular networks of mitochondria, division is clearly complemented by mitochondrial fusion. FtsZ is no longer used by these complex eukaryotes, and may have been replaced by other proteins better suited to sustaining complex mitochondrial networks. Although proteins that divide mitochondria from the inside are just beginning to be characterized in higher eukaryotes, many division proteins are known to act on the outside of the organelle. The most widespread of these are the dynamin-like proteins, which appear to have been recruited very early in the evolution of mitochondria. The essential nature of mitochondria dictates that their loss is intolerable to human cells, and that mutations disrupting mitochondrial division are more likely to be fatal than result in disease. To date, only one disease (Charcot-Marie-Tooth disease 2A) has been mapped to a gene that is required for mitochondrial division, whereas two other diseases can be attributed to mutations in mitochondrial fusion genes. Apart from playing a role in regulating the morphology, which might be important for efficient ATP production, research has indicated that the mitochondrial division and fusion proteins can also be important during apoptosis; mitochondrial fragmentation is an early triggering (and under many stimuli, essential) step in the pathway to cell suicide.
Collapse
Affiliation(s)
- Ben R Kiefel
- Center for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Melbourne, Australia
| | | | | |
Collapse
|
44
|
Abstract
Correct positioning and active movement of organelles within cells are essential for cellular homeostasis and adaptation to external stresses. Unlike animal and fungal systems, plant organelle positioning has not yet been revealed at the molecular level. The recent development of organelle-targeting green fluorescent protein (GFP) constructs and genetic analyses using Arabidopsis thaliana have shed new light on the field of plant organelle positioning, which has been found to be regulated by mechanisms that are similar to and/or distinct from those used by animals and fungi.
Collapse
Affiliation(s)
- Masamitsu Wada
- Department of Biological Sciences, Graduate School of Science, Tokyo Metropolitan University, Tokyo 192-0397, Japan.
| | | |
Collapse
|
45
|
Abstract
Mitochondria cannot be created de novo but instead must arise from the fission (division) of a parental organelle. In addition to fission, mitochondria also fuse with one another and it is thought that a co-ordinated balance of these two processes controls mitochondrial shape, size and number. In the past 5-7 yr, molecular genetics coupled to state-of-the-art cell biology, in particular the use of mitochondrial-targeted green fluorescent protein (GFP), has enabled identification of proteins controlling mitochondrial shape, size and number in yeast and mammalian cells. Little is known about higher plant mitochondrial dynamics. Recently, however, several genes involved in the control of plant mitochondrial dynamics have been identified. The aim of this article is to bring together what is known about mitochondrial dynamics in any organisms and to relate this to our recent knowledge of the underlying processes in higher plants. Contents Summary 463 I. Introduction 464 II. Mitochondrial evolution 464 III. Mitochondria and the cytoskeleton 465 IV. Mitochondrial morphology, biogenesis, proliferation and inheritance 466 V. Mitochondrial fission and fusion 468 VI. Mitochondrial distribution 470 VII. Plant specific proteins playing a role in mitochondrial dynamics 470 VIII. Conclusions 471 Acknowledgements 475 References 475.
Collapse
Affiliation(s)
- David C Logan
- School of Biology, Sir Harold Mitchell Building, University of St Andrews, St Andrews, KY16 9TH, UK
| |
Collapse
|
46
|
Gilson PR, Yu XC, Hereld D, Barth C, Savage A, Kiefel BR, Lay S, Fisher PR, Margolin W, Beech PL. Two Dictyostelium orthologs of the prokaryotic cell division protein FtsZ localize to mitochondria and are required for the maintenance of normal mitochondrial morphology. EUKARYOTIC CELL 2003; 2:1315-26. [PMID: 14665465 PMCID: PMC326642 DOI: 10.1128/ec.2.6.1315-1326.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2003] [Accepted: 08/13/2003] [Indexed: 11/20/2022]
Abstract
In bacteria, the protein FtsZ is the principal component of a ring that constricts the cell at division. Though all mitochondria probably arose through a single, ancient bacterial endosymbiosis, the mitochondria of only certain protists appear to have retained FtsZ, and the protein is absent from the mitochondria of fungi, animals, and higher plants. We have investigated the role that FtsZ plays in mitochondrial division in the genetically tractable protist Dictyostelium discoideum, which has two nuclearly encoded FtsZs, FszA and FszB, that are targeted to the inside of mitochondria. In most wild-type amoebae, the mitochondria are spherical or rod-shaped, but in fsz-null mutants they become elongated into tubules, indicating that a decrease in mitochondrial division has occurred. In support of this role in organelle division, antibodies to FszA and FszA-green fluorescent protein (GFP) show belts and puncta at multiple places along the mitochondria, which may define future or recent sites of division. FszB-GFP, in contrast, locates to an electron-dense, submitochondrial body usually located at one end of the organelle, but how it functions during division is unclear. This is the first demonstration of two differentially localized FtsZs within the one organelle, and it points to a divergence in the roles of these two proteins.
Collapse
Affiliation(s)
- Paul R Gilson
- Centre for Cellular and Molecular Biology, School of Biological and Chemical Sciences, Deakin University, Victoria 3125, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Logan DC, Scott I, Tobin AK. The genetic control of plant mitochondrial morphology and dynamics. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2003; 36:500-509. [PMID: 14617080 DOI: 10.1046/j.1365-313x.2003.01894.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Little is known about the genetic control of mitochondrial morphology and dynamics in higher plants. We used a genetic screen involving fluorescence microscopic analysis of ethyl methane sulphonate (EMS)-mutated Arabidopsis thaliana seedlings expressing GFP targeted to mitochondria to isolate eight mutants displaying distinct perturbations of the normal mitochondrial morphology or distribution. We describe five mutants with distinct and unique mitochondrial phenotypes, which map to five different loci, not previously implicated in mitochondrial behaviour in plants. We have used a combination of forward and reverse genetics to identify one of the genes, friendly mitochondria (FMT), a homologue of the CluA gene of Dictyostelium discoideum, which is involved in the correct distribution of mitochondria in the cell. The five mutants constitute a powerful resource to aid our understanding of mitochondrial dynamics in higher plants.
Collapse
Affiliation(s)
- David C Logan
- School of Biology, Sir Harold Mitchell Building, University of St Andrews, St Andrews, Fife KY16 9TH, Scotland, UK.
| | | | | |
Collapse
|
48
|
Dimmer KS, Fritz S, Fuchs F, Messerschmitt M, Weinbach N, Neupert W, Westermann B. Genetic basis of mitochondrial function and morphology in Saccharomyces cerevisiae. Mol Biol Cell 2002; 13:847-53. [PMID: 11907266 PMCID: PMC99603 DOI: 10.1091/mbc.01-12-0588] [Citation(s) in RCA: 348] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The understanding of the processes underlying organellar function and inheritance requires the identification and characterization of the molecular components involved. We pursued a genomic approach to define the complements of genes required for respiratory growth and inheritance of mitochondria with normal morphology in yeast. With the systematic screening of a deletion mutant library covering the nonessential genes of Saccharomyces cerevisiae the numbers of genes known to be required for respiratory function and establishment of wild-type-like mitochondrial structure have been more than doubled. In addition to the identification of novel components, the systematic screen revealed unprecedented mitochondrial phenotypes that have never been observed by conventional screens. These data provide a comprehensive picture of the cellular processes and molecular components required for mitochondrial function and structure in a simple eukaryotic cell.
Collapse
Affiliation(s)
- Kai Stefan Dimmer
- Institut für Physiologische Chemie der Universität München, D-81377 München, Germany
| | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
The roles of mitochondria in cell death and in aging have generated much excitement in recent years. At the same time, however, a quiet revolution in our thinking about mitochondrial ultrastructure has begun. This revolution started with the use of vital dyes and of green fluorescent protein fusion proteins, showing that mitochondria are very dynamic structures that constantly move, divide and fuse throughout the life of a cell. More recently, some of the first proteins contributing to these various processes have been discovered. Our view of the internal structures of mitochondria has also changed. Three-dimensional reconstructions obtained with high voltage electron microscopy show that cristae are often connected to the mitochondrial inner membrane by thin tubules. These new insights are brought to bear on the wealth of data collected by conventional electron microscopic analysis.
Collapse
Affiliation(s)
- L Griparic
- Department of Biological Chemistry, University of California, Los Angeles CA 90095, USA
| | | |
Collapse
|
50
|
MacWilliams H, Gaudet P, Deichsel H, Bonfils C, Tsang A. Biphasic expression of rnrB in Dictyostelium discoideum suggests a direct relationship between cell cycle control and cell differentiation. Differentiation 2001; 67:12-24. [PMID: 11270119 DOI: 10.1046/j.1432-0436.2001.067001012.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell differentiation in Dictyostelium is strongly affected by the cell cycle. Cell cycle control is well-understood in other systems, but this has had almost no impact on the study of Dictyostelium cell differentiation, in part because the cell cycle in Dictyostelium is unusual, lacking a G1 phase. Here we describe the cell-cycle regulated expression of rnrB, which codes for the small subunit of ribonucleotide reductase and is a marker of late G1 in many systems. There appear to be two expression peaks, one in mid-G2 and the other near the G2/M transition. Using Xgal/anti-BrdU double staining, we show that cells in asynchronously growing cultures express in both phases, with a gap between them during which the gene is transcriptionally silent. Cold-synchronized cells show exclusively G2/M expression, while mid-G2 expression is seen in high-density synchronized cells and can also be inferred in cells undergoing synchronization by either method. rnrB expression occurs in other systems shortly after cells pass a point (the "restriction point" or "start") at which they commit to complete their current cell cycle. We demonstrate a similar commitment point in Dictyostelium and show that this occurs shortly before the mid-G2 rnrB expression peak. The Dictyostelium cell cycle thus appears to include a well-defined though inconspicuous event, between early and mid-G2, with some features which are normally associated with the G1/S transition. Others have described a switch from stalk to spore differentiation preference at about this time. Since Dictyostelium cells switch back from spore to stalk preference approximately at the G2/M rnrB expression maximum, cell differentiation as well as rnrB expression may be regulated directly by fundamental cell cycle control processes.
Collapse
Affiliation(s)
- H MacWilliams
- Zoologisches Institut, Ludwig-Maximilians-Universitat Luisenstrasse 14, 80333 München 2, Germany.
| | | | | | | | | |
Collapse
|