201
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Tucker K, Park E. Cryo-EM structure of the mitochondrial protein-import channel TOM complex at near-atomic resolution. Nat Struct Mol Biol 2019; 26:1158-1166. [PMID: 31740857 DOI: 10.1038/s41594-019-0339-2] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/23/2019] [Indexed: 11/09/2022]
Abstract
Nearly all mitochondrial proteins are encoded by the nuclear genome and imported into mitochondria after synthesis on cytosolic ribosomes. These precursor proteins are translocated into mitochondria by the TOM complex, a protein-conducting channel in the mitochondrial outer membrane. We have determined high-resolution cryo-EM structures of the core TOM complex from Saccharomyces cerevisiae in dimeric and tetrameric forms. Dimeric TOM consists of two copies each of five proteins arranged in two-fold symmetry: pore-forming β-barrel protein Tom40 and four auxiliary α-helical transmembrane proteins. The pore of each Tom40 has an overall negatively charged inner surface attributed to multiple functionally important acidic patches. The tetrameric complex is essentially a dimer of dimeric TOM, which may be capable of forming higher-order oligomers. Our study reveals the detailed molecular organization of the TOM complex and provides new insights about the mechanism of protein translocation into mitochondria.
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Affiliation(s)
- Kyle Tucker
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Eunyong Park
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA. .,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA, USA.
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202
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Favia M, de Bari L, Bobba A, Atlante A. An Intriguing Involvement of Mitochondria in Cystic Fibrosis. J Clin Med 2019; 8:jcm8111890. [PMID: 31698802 PMCID: PMC6912654 DOI: 10.3390/jcm8111890] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/31/2019] [Accepted: 11/04/2019] [Indexed: 12/16/2022] Open
Abstract
Cystic fibrosis (CF) occurs when the cystic fibrosis transmembrane conductance regulator (CFTR) protein is not synthetized and folded correctly. The CFTR protein helps to maintain the balance of salt and water on many body surfaces, such as the lung surface. When the protein is not working correctly, chloride becomes trapped in cells, then water cannot hydrate the cellular surface and the mucus covering the cells becomes thick and sticky. Furthermore, a defective CFTR appears to produce a redox imbalance in epithelial cells and extracellular fluids and to cause an abnormal generation of reactive oxygen species: as a consequence, oxidative stress has been implicated as a causative factor in the aetiology of the process. Moreover, massive evidences show that defective CFTR gives rise to extracellular GSH level decrease and elevated glucose concentrations in airway surface liquid (ASL), thus encouraging lung infection by pathogens in the CF advancement. Recent research in progress aims to rediscover a possible role of mitochondria in CF. Here the latest new and recent studies on mitochondrial bioenergetics are collected. Surprisingly, they have enabled us to ascertain that mitochondria have a leading role in opposing the high ASL glucose level as well as oxidative stress in CF.
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Affiliation(s)
- Maria Favia
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari, Via E. Orabona 4, 70126 Bari, Italy
- Correspondence: (M.F.); (A.A.)
| | - Lidia de Bari
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
| | - Antonella Bobba
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
| | - Anna Atlante
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari—CNR, Via G. Amendola 122/O, 70126 Bari, Italy; (L.d.B.); (A.B.)
- Correspondence: (M.F.); (A.A.)
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203
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Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Burgstaller S, Bischof H, Koshenov Z, Gottschalk B, Malli R, Graier WF. Tracking intra- and inter-organelle signaling of mitochondria. FEBS J 2019; 286:4378-4401. [PMID: 31661602 PMCID: PMC6899612 DOI: 10.1111/febs.15103] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/19/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Mitochondria are as highly specialized organelles and masters of the cellular energy metabolism in a constant and dynamic interplay with their cellular environment, providing adenosine triphosphate, buffering Ca2+ and fundamentally contributing to various signaling pathways. Hence, such broad field of action within eukaryotic cells requires a high level of structural and functional adaptation. Therefore, mitochondria are constantly moving and undergoing fusion and fission processes, changing their shape and their interaction with other organelles. Moreover, mitochondrial activity gets fine-tuned by intra- and interorganelle H+ , K+ , Na+ , and Ca2+ signaling. In this review, we provide an up-to-date overview on mitochondrial strategies to adapt and respond to, as well as affect, their cellular environment. We also present cutting-edge technologies used to track and investigate subcellular signaling, essential to the understanding of various physiological and pathophysiological processes.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,Department of Health Sciences and Technology, ETH Zurich, Schwerzenbach, Switzerland
| | - Jeta Ramadani-Muja
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Gabriela Ziomek
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Zhanat Koshenov
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Benjamin Gottschalk
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
| | - Wolfgang F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Austria.,BioTechMed, Graz, Austria
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204
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Vazquez-Calvo C, Suhm T, Büttner S, Ott M. The basic machineries for mitochondrial protein quality control. Mitochondrion 2019; 50:121-131. [PMID: 31669238 DOI: 10.1016/j.mito.2019.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/10/2019] [Accepted: 10/02/2019] [Indexed: 11/16/2022]
Abstract
Mitochondria play pivotal roles in cellular energy metabolism, the synthesis of essential biomolecules and the regulation of cell death and aging. The proper folding, unfolding and degradation of the many proteins active within mitochondria is surveyed by the mitochondrial quality control machineries. Here, we describe the principal components of the mitochondrial quality control system and recent developments in the elucidation of the molecular mechanisms maintaining a functional mitochondrial proteome.
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Affiliation(s)
- Carmela Vazquez-Calvo
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrheniusväg 16, Stockholm 106 91, Sweden; Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, Stockholm 106 91, Sweden
| | - Tamara Suhm
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrheniusväg 16, Stockholm 106 91, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrheniusväg 20C, Stockholm 106 91, Sweden; Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, Graz 8010, Austria.
| | - Martin Ott
- Department of Biochemistry and Biophysics, Stockholm University, Svante Arrheniusväg 16, Stockholm 106 91, Sweden.
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205
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Wei SS, Niu WT, Zhai XT, Liang WQ, Xu M, Fan X, Lv TT, Xu WY, Bai JT, Jia N, Li B. Arabidopsis mtHSC70-1 plays important roles in the establishment of COX-dependent respiration and redox homeostasis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:5575-5590. [PMID: 31384929 DOI: 10.1093/jxb/erz357] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/20/2019] [Indexed: 05/16/2023]
Abstract
The 70 kDa heat shock proteins function as molecular chaperones and are involved in diverse cellular processes. However, the functions of the plant mitochondrial HSP70s (mtHSC70s) remain unclear. Severe growth defects were observed in the Arabidopsis thaliana mtHSC70-1 knockout lines, mthsc70-1a and mthsc70-1b. Conversely, the introduction of the mtHSC70-1 gene into the mthsc70-1a background fully reversed the phenotypes, indicating that mtHSC70-1 is essential for plant growth. The loss of mtHSC70-1 functions resulted in abnormal mitochondria and alterations to respiration because of an inhibition of the cytochrome c oxidase (COX) pathway and the activation of the alternative respiratory pathway. Defects in COX assembly were observed in the mtHSC70-1 knockout lines, leading to decreased COX activity. The mtHSC70-1 knockout plants have increased levels of reactive oxygen species (ROS). The introduction of the Mn-superoxide dismutase 1 (MSD1) or the catalase 1 (CAT1) gene into the mthsc70-1a plants decreased ROS levels, reduced the expression of alternative oxidase, and partially rescued growth. Taken together, our data suggest that mtHSC70-1 plays important roles in the establishment of COX-dependent respiration.
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Affiliation(s)
- Shan-Shan Wei
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Wei-Tao Niu
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
- College of Biological Science and Engineering, Xingtai University, Xingtai, China
| | - Xiao-Ting Zhai
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Wei-Qian Liang
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Meng Xu
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Xiao Fan
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Ting-Ting Lv
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Wen-Yan Xu
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Jiao-Teng Bai
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Ning Jia
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Bing Li
- Hebei Key Laboratory of Molecular and Cellular Biology, Hebei Collaboration Innovation Center for Cell Signaling, Key Laboratory of Molecular and Cellular Biology of Ministry of Education, College of Life Science, Hebei Normal University, Shijiazhuang, China
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206
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Huang Z, Zhao Q, Chen M, Zhang J, Ji L. Liquiritigenin and liquiritin alleviated monocrotaline-induced hepatic sinusoidal obstruction syndrome via inhibiting HSP60-induced inflammatory injury. Toxicology 2019; 428:152307. [PMID: 31589899 DOI: 10.1016/j.tox.2019.152307] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 09/25/2019] [Accepted: 10/02/2019] [Indexed: 02/06/2023]
Abstract
Hepatic sinusoidal obstruction syndrome (HSOS) is a life-threatening liver disease caused by the damage to liver sinusoidal endothelial cells (LSECs). Liquiritigenin and liquiritin are two main compounds in Glycyrrhizae Radix et Rhizoma (Gan-cao). Our previous study has shown that both liquiritigenin and liquiritin alleviated monocrotaline (MCT)-induced HSOS in rats via inducing the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant signaling pathway. This study aims to further investigate whether inhibiting liver inflammatory injury also contributed to the liquiritigenin and liquiritin-provided alleviation on MCT-induced HSOS. The results of serum alanine/aspartate aminotransferases (ALT/AST) activities and total bilirubin (TBil) amount, liver histological evaluation, scanning electron microscope observation and hepatic metalloproteinase-9 (MMP9) expression showed that liquiritigenin and liquiritin both alleviated MCT-induced HSOS in rats. Liquiritigenin and liquiritin reduced the increased liver myeloperoxidase (MPO) activity, mRNA expression of pro-inflammatory factors, hepatic infiltration of immune cells, hepatic toll-like receptor 4 (TLR4) expression and nuclear factor κB (NFκB) nuclear accumulation induced by MCT in rats. Furthermore, liquiritigenin and liquiritin attenuated MCT-induced liver mitochondrial injury, increased the decreased Lon protein expression and reduced the release of heat shock protein 60 (HSP60). Moreover, liquiritigenin and liquiritin also reduced NFκB nuclear accumulation and decreased the elevated cellular mRNA expression of NFκB-downstream pro-inflammatory cytokines induced by HSP60 in macrophage RAW264.7 cells. In conclusion, our study revealed that both liquiritigenin and liquiritin alleviated MCT-induced HSOS by inhibiting hepatic inflammatory responses triggered by HSP60.
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Affiliation(s)
- Zhenlin Huang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Qing Zhao
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Minwei Chen
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Jingnan Zhang
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Lili Ji
- The MOE Key Laboratory for Standardization of Chinese Medicines, Shanghai Key Laboratory of Compound Chinese Medicines and the SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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207
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Bublitz DC, Chadwick GL, Magyar JS, Sandoz KM, Brooks DM, Mesnage S, Ladinsky MS, Garber AI, Bjorkman PJ, Orphan VJ, McCutcheon JP. Peptidoglycan Production by an Insect-Bacterial Mosaic. Cell 2019; 179:703-712.e7. [PMID: 31587897 PMCID: PMC6838666 DOI: 10.1016/j.cell.2019.08.054] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 08/06/2019] [Accepted: 08/28/2019] [Indexed: 01/19/2023]
Abstract
Peptidoglycan (PG) is a defining feature of bacteria, involved in cell division, shape, and integrity. We previously reported that several genes related to PG biosynthesis were horizontally transferred from bacteria to the nuclear genome of mealybugs. Mealybugs are notable for containing a nested bacteria-within-bacterium endosymbiotic structure in specialized insect cells, where one bacterium, Moranella, lives in the cytoplasm of another bacterium, Tremblaya. Here we show that horizontally transferred genes on the mealybug genome work together with genes retained on the Moranella genome to produce a PG layer exclusively at the Moranella cell periphery. Furthermore, we show that an insect protein encoded by a horizontally transferred gene of bacterial origin is transported into the Moranella cytoplasm. These results provide a striking parallel to the genetic and biochemical mosaicism found in organelles, and prove that multiple horizontally transferred genes can become integrated into a functional pathway distributed between animal and bacterial endosymbiont genomes. Mealybugs have two bacterial endosymbionts; one symbiont lives inside the other The mealybug genome has acquired some bacterial peptidoglycan (PG)-related genes This insect-symbiont mosaic pathway produces a PG layer at the innermost symbiont Endosymbionts and organelles have evolved similar levels of biochemical integration
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Affiliation(s)
- DeAnna C Bublitz
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Grayson L Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - John S Magyar
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Kelsi M Sandoz
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, NIH, Hamilton, MT 59840, USA
| | - Diane M Brooks
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Stéphane Mesnage
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield S10 2TN, UK
| | - Mark S Ladinsky
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Arkadiy I Garber
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Pamela J Bjorkman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - John P McCutcheon
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA.
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208
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Bernal M, Yang X, Lisby M, Mazón G. The FANCM family Mph1 helicase localizes to the mitochondria and contributes to mtDNA stability. DNA Repair (Amst) 2019; 82:102684. [DOI: 10.1016/j.dnarep.2019.102684] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/31/2019] [Accepted: 08/03/2019] [Indexed: 11/24/2022]
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209
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Wein T, Romero Picazo D, Blow F, Woehle C, Jami E, Reusch TB, Martin WF, Dagan T. Currency, Exchange, and Inheritance in the Evolution of Symbiosis. Trends Microbiol 2019; 27:836-849. [DOI: 10.1016/j.tim.2019.05.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/19/2019] [Accepted: 05/30/2019] [Indexed: 12/28/2022]
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210
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Sachdeva A, Rajguru JP, Sohi K, Sachdeva SS, Kaur K, Devi R, Rana V. Association of leukemia and mitochondrial diseases-A review. J Family Med Prim Care 2019; 8:3120-3124. [PMID: 31742129 PMCID: PMC6857401 DOI: 10.4103/jfmpc.jfmpc_679_19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 08/23/2019] [Accepted: 09/19/2019] [Indexed: 11/04/2022] Open
Abstract
Mitochondria play an important role in various metabolic pathways like oxidative phosphorylation free radical generation and apoptosis. Defects in mitochondrial function are responsible for a number of heterogenous clinical presentations along with development and progression of cancer. Decrease in cellular energy (ATP) production because of impaired oxidative phosphorylation is the most important cause for these underlying disorders. The present review article aims to provide current understanding of mitochondrial genetics and biology and relates the mt-DNA alterations in leukemia patients.
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Affiliation(s)
- Ashwani Sachdeva
- Department of Prosthodontics, J.C.D Dental College, Sirsa, Haryana, India
| | - Jagadish Prasad Rajguru
- Department of Oral and Maxillofacial Pathology, Hi-Tech Dental College and Hospital, Bhubaneswar, Odisha, India
| | - Kanwardeep Sohi
- Department of Prosthodontics, Shaheed Kartar Singh Sarabha Dental College and Hospital, Sarabha, Ludhiana, Punjab, India
| | | | - Kirandeep Kaur
- Department of Public Health Dentistry, Shaheed Kartar Singh Sarabha Dental College and Hospital, Sarabha, Ludhiana, Punjab, India
| | - Rani Devi
- Department of Public Health Dentistry, Shaheed Kartar Singh Sarabha Dental College and Hospital, Sarabha, Ludhiana, Punjab, India
| | - Vivek Rana
- Department of Oral Medicine, Private Practitioner, New Delhi, India
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211
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Noncanonical mitochondrial unfolded protein response impairs placental oxidative phosphorylation in early-onset preeclampsia. Proc Natl Acad Sci U S A 2019; 116:18109-18118. [PMID: 31439814 PMCID: PMC6731647 DOI: 10.1073/pnas.1907548116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Preeclampsia endangers the lives and well-being of mother and baby. The syndrome is associated with placental dysfunction. High demand for energy to support active nutrient transport and hormone production increases placental susceptibility to mitochondrial stress. Here, we investigate mitochondrial activity and explore stress-response pathways in preeclamptic placentas. We demonstrate activation of noncanonical mitochondrial unfolded protein response (UPRmt) pathways associated with reduced CLPP, a key protease in UPRmt signalling, that compromises mitochondrial respiration. The changes can be recapitulated in trophoblast cells by hypoxia–reoxygenation. Either activation of UPRmt or knockdown of CLPP can sufficiently reduce mitochondrial respiration. Translation of CLPP is negatively regulated by the endoplasmic reticulum UPR pathway. Understanding mitochondrial stress provides new insights into the pathophysiology of early-onset preeclampsia. Preeclampsia (PE) is a dangerous complication of pregnancy, especially when it presents at <34 wk of gestation (PE < 34 wk). It is a major cause of maternal and fetal morbidity and mortality and also increases the risk of cardiometabolic diseases in later life for both mother and offspring. Placental oxidative stress induced by defective placentation sits at the epicenter of the pathophysiology. The placenta is susceptible to activation of the unfolded protein response (UPR), and we hypothesized this may affect mitochondrial function. We first examined mitochondrial respiration before investigating evidence of mitochondrial UPR (UPRmt) in placentas of PE < 34 wk patients. Reduced placental oxidative phosphorylation (OXPHOS) capacity measured in situ was observed despite no change in protein or mRNA levels of electron transport chain complexes. These results were fully recapitulated by subjecting trophoblast cells to repetitive hypoxia–reoxygenation and were associated with activation of a noncanonical UPRmt pathway; the quality-control protease CLPP, central to UPRmt signal transduction, was reduced, while the cochaperone, TID1, was increased. Transcriptional factor ATF5, which regulates expression of key UPRmt genes including HSP60 and GRP75, showed no nuclear translocation. Induction of the UPRmt with methacycline reduced OXPHOS capacity, while silencing CLPP was sufficient to reduce OXPHOS capacity, membrane potential, and promoted mitochondrial fission. CLPP was negatively regulated by the PERK-eIF2α arm of the endoplasmic reticulum UPR pathway, independent of ATF4. Similar changes in the UPRmt pathway were observed in placentas from PE < 34 wk patients. Our results identify UPRmt as a therapeutic target for restoration of placental function in early-onset preeclampsia.
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212
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Conformational ensemble of an intrinsically flexible loop in mitochondrial import protein Tim21 studied by modeling and molecular dynamics simulations. Biochim Biophys Acta Gen Subj 2019; 1864:129417. [PMID: 31445064 DOI: 10.1016/j.bbagen.2019.129417] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 08/12/2019] [Accepted: 08/17/2019] [Indexed: 11/20/2022]
Abstract
BACKGROUND Tim21, a subunit of a highly dynamic translocase of the inner mitochondrial membrane (TIM23) complex, translocates proteins by interacting with subunits in the translocase of the outer membrane (TOM) complex and Tim23 channel in the TIM23 complex. A loop segment in Tim21, which is in close proximity of the binding site of Tim23, has different conformations in X-ray, NMR and new crystal contact-free space (CCFS) structures. MD simulations can provide information on the structure and dynamics of the loop in solution. METHODS The conformational ensemble of the loop was characterized using loop modeling and molecular dynamics (MD) simulations. RESULTS MD simulations confirmed mobility of the loop. Multidimensional scaling and clustering were used to characterize the dynamic conformational ensemble of the loop. Free energy landscape showed that the CCFS crystal structure occupied a low energy region as compared to the conventional X-ray crystal structure. Analysis of crystal packing indicates that the CCFS provides larger conformational space for the motions of the loop. CONCLUSIONS Our work reported the conformational ensemble of the loop in solution, which is in agreement with the structure obtained from CCFS approach. The combination of the experimental techniques and computational methods is beneficial for studying highly flexible regions of proteins. GENERAL SIGNIFICANCE Computational methods, such as loop modeling and MD simulations, have proved to be useful for studying conformational flexibility of proteins. These methods in integration with experimental techniques such as CCFS has the potential to transform the studies on flexible regions of proteins.
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213
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Mandal A, Drerup CM. Axonal Transport and Mitochondrial Function in Neurons. Front Cell Neurosci 2019; 13:373. [PMID: 31447650 PMCID: PMC6696875 DOI: 10.3389/fncel.2019.00373] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 07/30/2019] [Indexed: 12/31/2022] Open
Abstract
The complex and elaborate architecture of a neuron poses a great challenge to the cellular machinery which localizes proteins and organelles, such as mitochondria, to necessary locations. Proper mitochondrial localization in neurons is particularly important as this organelle provides energy and metabolites essential to form and maintain functional neural connections. Consequently, maintenance of a healthy pool of mitochondria and removal of damaged organelles are essential for neuronal homeostasis. Long distance transport of the organelle itself as well as components necessary for maintaining mitochondria in distal compartments are important for a constant supply of healthy mitochondria at the right time and place. Accordingly, many neurodegenerative diseases have been associated with mitochondrial abnormalities. Here, we review our current understanding on transport-dependent mechanisms that regulate mitochondrial replenishment. We focus on axonal transport and import of mRNAs and proteins destined for mitochondria as well as mitochondrial fusion and fission to maintain mitochondrial homeostasis in distal compartments of the neuron.
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Affiliation(s)
- Amrita Mandal
- Unit on Neuronal Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Catherine M Drerup
- Unit on Neuronal Cell Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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214
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Cohen‐Erez I, Harduf N, Rapaport H. Oligonucleotide loaded polypeptide‐peptide nanoparticles towards mitochondrial‐targeted delivery. POLYM ADVAN TECHNOL 2019. [DOI: 10.1002/pat.4707] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Ifat Cohen‐Erez
- Avram and Stella Goldstein‐Goren Department of Biotechnology EngineeringBen‐Gurion University of the Negev Beer‐Sheva Israel
| | - Noa Harduf
- Avram and Stella Goldstein‐Goren Department of Biotechnology EngineeringBen‐Gurion University of the Negev Beer‐Sheva Israel
| | - Hanna Rapaport
- Avram and Stella Goldstein‐Goren Department of Biotechnology EngineeringBen‐Gurion University of the Negev Beer‐Sheva Israel
- Ilse Katz Institute for Nanoscale Science and Technology (IKI)Ben‐Gurion University of the Negev Beer‐Sheva Israel
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215
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Mitochondrial Homeostasis and Cellular Senescence. Cells 2019; 8:cells8070686. [PMID: 31284597 PMCID: PMC6678662 DOI: 10.3390/cells8070686] [Citation(s) in RCA: 119] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/02/2019] [Accepted: 07/05/2019] [Indexed: 01/07/2023] Open
Abstract
Cellular senescence refers to a stress response aiming to preserve cellular and, therefore, organismal homeostasis. Importantly, deregulation of mitochondrial homeostatic mechanisms, manifested as impaired mitochondrial biogenesis, metabolism and dynamics, has emerged as a hallmark of cellular senescence. On the other hand, impaired mitostasis has been suggested to induce cellular senescence. This review aims to provide an overview of homeostatic mechanisms operating within mitochondria and a comprehensive insight into the interplay between cellular senescence and mitochondrial dysfunction.
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216
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Becker T, Song J, Pfanner N. Versatility of Preprotein Transfer from the Cytosol to Mitochondria. Trends Cell Biol 2019; 29:534-548. [PMID: 31030976 DOI: 10.1016/j.tcb.2019.03.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 11/16/2022]
Abstract
Mitochondrial biogenesis requires the import of a large number of precursor proteins from the cytosol. Although specific membrane-bound preprotein translocases have been characterized in detail, it was assumed that protein transfer from the cytosol to mitochondria mainly involved unselective binding to molecular chaperones. Recent findings suggest an unexpected versatility of protein transfer to mitochondria. Cytosolic factors have been identified that bind to selected subsets of preproteins and guide them to mitochondrial receptors in a post-translational manner. Cotranslational import processes are emerging. Mechanisms for crosstalk between protein targeting to mitochondria and other cell organelles, in particular the endoplasmic reticulum (ER) and peroxisomes, have been uncovered. We discuss how a network of cytosolic machineries and targeting pathways promote and regulate preprotein transfer into mitochondria.
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Affiliation(s)
- Thomas Becker
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Centre for Integrative Biological Signaling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
| | - Jiyao Song
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Centre for Integrative Biological Signaling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
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217
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Abstract
Candida albicans is an opportunistic fungal pathogen of major clinical concern. The virulence of this pathogen is intimately intertwined with its metabolism. Mitochondria, which have a central metabolic role, have undergone many lineage-specific adaptations in association with their eukaryotic host. A screen for lineage-specific genes identified seven such genes specific to the CTG clade of fungi, of which C. albicans is a member. Each is required for respiratory growth and is integral to expression of complex I, III, or IV of the electron transport chain. Two genes, NUO3 and NUO4, encode supernumerary subunits of complex I, whereas NUE1 and NUE2 have nonstructural roles in expression of complex I. Similarly, the other three genes have nonstructural roles in expression of complex III (QCE1) or complex IV (COE1 and COE2). In addition to these novel additions, an alternative functional assignment was found for the mitochondrial protein encoded by MNE1 MNE1 was required for complex I expression in C. albicans, whereas the distantly related Saccharomyces cerevisiae ortholog participates in expression of complex III. Phenotypic analysis of deletion mutants showed that fermentative metabolism is unable to support optimal growth rates or yields of C. albicans However, yeast-hypha morphogenesis, an important virulence attribute, did not require respiratory metabolism under hypoxic conditions. The inability to respire also resulted in hypersensitivity to the antifungal fluconazole and in attenuated virulence in a Galleria mellonella infection model. The results show that lineage-specific adaptations have occurred in C. albicans mitochondria and highlight the significance of respiratory metabolism in the pathobiology of C. albicans IMPORTANCE Candida albicans is an opportunistic fungal pathogen of major clinical concern. The virulence of this pathogen is intimately intertwined with its metabolic behavior, and mitochondria have a central role in that metabolism. Mitochondria have undergone many evolutionary changes, which include lineage-specific adaptations in association with their eukaryotic host. Seven lineage-specific genes required for electron transport chain function were identified in the CTG clade of fungi, of which C. albicans is a member. Additionally, examination of several highly diverged orthologs encoding mitochondrial proteins demonstrated functional reassignment for one of these. Deficits imparted by deletion of these genes revealed the critical role of respiration in virulence attributes of the fungus and highlight important evolutionary adaptations in C. albicans metabolism.
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218
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Lan B, He Y, Sun H, Zheng X, Gao Y, Li N. The roles of mitochondria-associated membranes in mitochondrial quality control under endoplasmic reticulum stress. Life Sci 2019; 231:116587. [PMID: 31220526 DOI: 10.1016/j.lfs.2019.116587] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/28/2019] [Accepted: 06/17/2019] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) and mitochondria are two important organelles in cells. Mitochondria-associated membranes (MAMs) are lipid raft-like domains formed in the ER membranes that are in close apposition to mitochondria. They play an important role in signal transmission between these two essential organelles. When cells are exposed to internal or external stressful stimuli, the ER will activate an adaptive response called the ER stress response, which has a significant effect on mitochondrial function. Mitochondrial quality control is an important mechanism to ensure the functional integrity of mitochondria and the effect of ER stress on mitochondrial quality control through MAMs is of great significance. Therefore, in this review, we introduce ER stress and mitochondrial quality control, and discuss how ER stress signals are transmitted to mitochondria through MAMs. We then review the important roles of MAMs in mitochondrial quality control under ER stress.
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Affiliation(s)
- Beiwu Lan
- Department of Neurosurgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin, China
| | - Yichun He
- Department of Neurosurgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin, China
| | - Hongyu Sun
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, China
| | - Xinzi Zheng
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, China
| | - Yufei Gao
- Department of Neurosurgery, China-Japan Union Hospital, Jilin University, Changchun, Jilin, China.
| | - Na Li
- Department of Pathophysiology, Key Laboratory of Pathobiology, Ministry of Education, College of Basic Medical Sciences, Jilin University, Changchun, Jilin, China.
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219
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Mitochondrial protein translocation-associated degradation. Nature 2019; 569:679-683. [PMID: 31118508 DOI: 10.1038/s41586-019-1227-y] [Citation(s) in RCA: 170] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 04/25/2019] [Indexed: 01/12/2023]
Abstract
Mitochondrial biogenesis and functions depend on the import of precursor proteins via the 'translocase of the outer membrane' (TOM complex). Defects in protein import lead to an accumulation of mitochondrial precursor proteins that induces a range of cellular stress responses. However, constitutive quality-control mechanisms that clear trapped precursor proteins from the TOM channel under non-stress conditions have remained unknown. Here we report that in Saccharomyces cerevisiae Ubx2, which functions in endoplasmic reticulum-associated degradation, is crucial for this quality-control process. A pool of Ubx2 binds to the TOM complex to recruit the AAA ATPase Cdc48 for removal of arrested precursor proteins from the TOM channel. This mitochondrial protein translocation-associated degradation (mitoTAD) pathway continuously monitors the TOM complex under non-stress conditions to prevent clogging of the TOM channel with precursor proteins. The mitoTAD pathway ensures that mitochondria maintain their full protein-import capacity, and protects cells against proteotoxic stress induced by impaired transport of proteins into mitochondria.
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220
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Sato TK, Kawano S, Endo T. Role of the membrane potential in mitochondrial protein unfolding and import. Sci Rep 2019; 9:7637. [PMID: 31114030 PMCID: PMC6529458 DOI: 10.1038/s41598-019-44152-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/10/2019] [Indexed: 12/02/2022] Open
Abstract
Newly synthesized mitochondrial precursor proteins have to become unfolded to cross the mitochondrial membranes. This unfolding is achieved primarily by mitochondrial Hsp70 (mtHsp70) for presequence-containing precursor proteins. However, the membrane potential across the inner membrane (ΔΨ) could also contribute to unfolding of short-presequence containing mitochondrial precursor proteins. Here we investigated the role of ΔΨ in mitochondrial protein unfolding and import. We found that the effects of mutations in the presequence on import rates are correlated well with the hydrophobicity or ability to interact with import motor components including mtHsp70, but not with ΔΨ (negative inside). A spontaneously unfolded precursor protein with a short presequence is therefore trapped by motor components including mtHsp70, but not ΔΨ, which could cause global unfolding of the precursor protein. Instead, ΔΨ may contribute the precursor unfolding by holding the presequence at the inner membrane for trapping of the unfolded species by the import motor system.
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Affiliation(s)
- Takehiro K Sato
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan.,Spiber Inc. 234-1 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, Japan
| | - Shin Kawano
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan.,Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan.,Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan
| | - Toshiya Endo
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, 464-8602, Japan. .,Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan. .,Institute for Protein Dynamics, Kyoto Sangyo University, Kamigamo-motoyama, Kita-ku, Kyoto, 603-8555, Japan.
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221
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Corcoles-Saez I, Ferat JL, Costanzo M, Boone CM, Cha RS. Functional link between mitochondria and Rnr3, the minor catalytic subunit of yeast ribonucleotide reductase. MICROBIAL CELL 2019; 6:286-294. [PMID: 31172013 PMCID: PMC6545439 DOI: 10.15698/mic2019.06.680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ribonucleotide reductase (RNR) is an essential holoenzyme required for de novo synthesis of dNTPs. The Saccharomyces cerevisiae genome encodes for two catalytic subunits, Rnr1 and Rnr3. While Rnr1 is required for DNA replication and DNA damage repair, the function(s) of Rnr3 is unknown. Here, we show that carbon source, an essential nutrient, impacts Rnr1 and Rnr3 abundance: Non-fermentable carbon sources or limiting concentrations of glucose down regulate Rnr1 and induce Rnr3 expression. Oppositely, abundant glucose induces Rnr1 expression and down regulates Rnr3. The carbon source dependent regulation of Rnr3 is mediated by Mec1, the budding yeast ATM/ATR checkpoint response kinase. Unexpectedly, this regulation is independent of all currently known components of the Mec1 DNA damage response network, including Rad53, Dun1, and Tel1, implicating a novel Mec1 signalling axis. rnr3Δ leads to growth defects under respiratory conditions and rescues temperature sensitivity conferred by the absence of Tom6, a component of the mitochondrial TOM (translocase of outer membrane) complex responsible for mitochondrial protein import. Together, these results unveil involvement of Rnr3 in mitochondrial functions and Mec1 in mediating the carbon source dependent regulation of Rnr3.
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Affiliation(s)
- Isaac Corcoles-Saez
- School of Medical Sciences, North West Cancer Research Institute, Bangor University, Deniol Road, Bangor, LL57 2UW, United Kingdom
| | - Jean-Luc Ferat
- Institute of Integrative Biology of the Cell (I2BC), Avenue de la Terrasse, Paris, France
| | - Michael Costanzo
- University of Toronto, Donnelly Centre, 160 College Street, Toronto, Ontario, M5S 3E1, Canada
| | - Charles M Boone
- University of Toronto, Donnelly Centre, 160 College Street, Toronto, Ontario, M5S 3E1, Canada
| | - Rita S Cha
- School of Medical Sciences, North West Cancer Research Institute, Bangor University, Deniol Road, Bangor, LL57 2UW, United Kingdom
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222
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Impaired Mitochondrial Fusion and Oxidative Phosphorylation Triggered by High Glucose Is Mediated by Tom22 in Endothelial Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4508762. [PMID: 31236191 PMCID: PMC6545771 DOI: 10.1155/2019/4508762] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/22/2019] [Accepted: 03/18/2019] [Indexed: 11/18/2022]
Abstract
Much evidence demonstrates that mitochondrial dysfunction plays a crucial role in the pathogenesis of vascular complications of diabetes. However, the signaling pathways through which hyperglycemia leads to mitochondrial dysfunction of endothelial cells are not fully understood. Here, we treated human umbilical vein endothelial cells (HUVECs) with high glucose and examined the role of translocase of mitochondrial outer membrane (Tom) 22 on mitochondrial dynamics and cellular function. Impaired Tom22 expression and protein expression of oxidative phosphorylation (OXPHOS) as well as decreased mitochondrial fusion were observed in HUVECs treated with high glucose. The deletion of Tom22 resulted in reduced mitochondrial fusion and ATP production and increased apoptosis in HUVECs. The overexpression of Tom22 restored the balance of mitochondrial dynamics and OXPHOS disrupted by high glucose. Importantly, we found that Tom22 modulates mitochondrial dynamics and OXPHOS by interacting with mitofusin (Mfn) 1. Taken together, our findings demonstrate for the first time that Tom22 is a novel regulator of both mitochondrial dynamics and bioenergetic function and contributes to cell survival following high-glucose exposure.
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223
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Weber C, Michaels T, Mahadevan L. Spatial control of irreversible protein aggregation. eLife 2019; 8:e42315. [PMID: 31084715 PMCID: PMC6516824 DOI: 10.7554/elife.42315] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 04/01/2019] [Indexed: 12/19/2022] Open
Abstract
Liquid cellular compartments form in the cyto- or nucleoplasm and can regulate aberrant protein aggregation. Yet, the mechanisms by which these compartments affect protein aggregation remain unknown. Here, we combine kinetic theory of protein aggregation and liquid-liquid phase separation to study the spatial control of irreversible protein aggregation in the presence of liquid compartments. We find that even for weak interactions aggregates strongly partition into the liquid compartment. Aggregate partitioning is caused by a positive feedback mechanism of aggregate nucleation and growth driven by a flux maintaining the phase equilibrium between the compartment and its surrounding. Our model establishes a link between specific aggregating systems and the physical conditions maximizing aggregate partitioning into the compartment. The underlying mechanism of aggregate partitioning could be used to confine cytotoxic protein aggregates inside droplet-like compartments but may also represent a common mechanism to spatially control irreversible chemical reactions in general.
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Affiliation(s)
- Christoph Weber
- School of Engineering and Applied SciencesHarvard UniversityCambridgeUnited States
| | - Thomas Michaels
- School of Engineering and Applied SciencesHarvard UniversityCambridgeUnited States
| | - L Mahadevan
- Department of PhysicsHarvard UniversityCambridgeUnited States
- Department of Organismic and Evolutionary BiologyHarvard UniversityCambridgeUnited States
- Kavli Institute for NanoBio Science and TechnologyHarvard UniversityCambridgeUnited States
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224
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Tran A. The N-end rule pathway and Ubr1 enforce protein compartmentalization via P2-encoded cellular location signals. J Cell Sci 2019; 132:jcs.231662. [PMID: 30940687 DOI: 10.1242/jcs.231662] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 03/22/2019] [Indexed: 12/24/2022] Open
Abstract
The Arg/N-end rule pathway and Ubr1, a ubiquitin E3 ligase conserved from yeast to humans, is involved in the degradation of misfolded proteins in the cytosol. However, the root physiological purpose of this activity is not completely understood. Through a systematic examination of single-residue P2-position mutants of misfolded proteins, and global and targeted bioinformatic analyses of the Saccharomyces cerevisiae proteome, it was determined that Ubr1 preferentially targets mistranslocated secretory and mitochondrial proteins in the cytosol. Degradation by Ubr1 is dependent on the recognition of cellular location signals that are naturally embedded into the second amino acid residue of most proteins. This P2-encoded location signaling mechanism may shed light on how Ubr1 and the N-end rule pathway are involved in neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. A corollary to this discovery is that the N-end rule pathway enforces the compartmentalization of secretory and mitochondrial proteins by degrading those that fail to reach their intended subcellular locations. The N-end rule pathway is therefore likely to have been critical to the evolution of endosymbiotic relationships that paved the way for advanced eukaryotic cellular life. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Anthony Tran
- National University of Singapore, Department of Biological Sciences, Singapore 117604
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225
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Mohanraj K, Wasilewski M, Benincá C, Cysewski D, Poznanski J, Sakowska P, Bugajska Z, Deckers M, Dennerlein S, Fernandez‐Vizarra E, Rehling P, Dadlez M, Zeviani M, Chacinska A. Inhibition of proteasome rescues a pathogenic variant of respiratory chain assembly factor COA7. EMBO Mol Med 2019; 11:emmm.201809561. [PMID: 30885959 PMCID: PMC6505684 DOI: 10.15252/emmm.201809561] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nuclear and mitochondrial genome mutations lead to various mitochondrial diseases, many of which affect the mitochondrial respiratory chain. The proteome of the intermembrane space (IMS) of mitochondria consists of several important assembly factors that participate in the biogenesis of mitochondrial respiratory chain complexes. The present study comprehensively analyzed a recently identified IMS protein cytochrome c oxidase assembly factor 7 (COA7), or RESpiratory chain Assembly 1 (RESA1) factor that is associated with a rare form of mitochondrial leukoencephalopathy and complex IV deficiency. We found that COA7 requires the mitochondrial IMS import and assembly (MIA) pathway for efficient accumulation in the IMS We also found that pathogenic mutant versions of COA7 are imported slower than the wild-type protein, and mislocalized proteins are degraded in the cytosol by the proteasome. Interestingly, proteasome inhibition rescued both the mitochondrial localization of COA7 and complex IV activity in patient-derived fibroblasts. We propose proteasome inhibition as a novel therapeutic approach for a broad range of mitochondrial pathologies associated with the decreased levels of mitochondrial proteins.
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Affiliation(s)
- Karthik Mohanraj
- Laboratory of Mitochondrial BiogenesisCentre of New TechnologiesUniversity of WarsawWarsawPoland,ReMedy International Research Agenda UnitCentre of New TechnologiesUniversity of WarsawWarsawPoland,Laboratory of Mitochondrial BiogenesisInternational Institute of Molecular and Cell BiologyWarsawPoland
| | - Michal Wasilewski
- Laboratory of Mitochondrial BiogenesisCentre of New TechnologiesUniversity of WarsawWarsawPoland,Laboratory of Mitochondrial BiogenesisInternational Institute of Molecular and Cell BiologyWarsawPoland
| | | | - Dominik Cysewski
- Mass Spectrometry LabDepartment of BiophysicsInstitute of Biochemistry and BiophysicsWarsawPoland
| | - Jaroslaw Poznanski
- Department of BiophysicsInstitute of Biochemistry and BiophysicsWarsawPoland
| | - Paulina Sakowska
- Laboratory of Mitochondrial BiogenesisInternational Institute of Molecular and Cell BiologyWarsawPoland
| | - Zaneta Bugajska
- Laboratory of Mitochondrial BiogenesisCentre of New TechnologiesUniversity of WarsawWarsawPoland
| | - Markus Deckers
- Department of Cellular BiochemistryUniversity of GöttingenGöttingenGermany
| | - Sven Dennerlein
- Department of Cellular BiochemistryUniversity of GöttingenGöttingenGermany
| | | | - Peter Rehling
- Department of Cellular BiochemistryUniversity of GöttingenGöttingenGermany,Max Planck Institute for Biophysical ChemistryGöttingenGermany
| | - Michal Dadlez
- Mass Spectrometry LabDepartment of BiophysicsInstitute of Biochemistry and BiophysicsWarsawPoland
| | - Massimo Zeviani
- MRC Mitochondrial Biology UnitUniversity of CambridgeCambridgeUK
| | - Agnieszka Chacinska
- Laboratory of Mitochondrial BiogenesisCentre of New TechnologiesUniversity of WarsawWarsawPoland,ReMedy International Research Agenda UnitCentre of New TechnologiesUniversity of WarsawWarsawPoland,Laboratory of Mitochondrial BiogenesisInternational Institute of Molecular and Cell BiologyWarsawPoland
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226
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Topf U, Uszczynska-Ratajczak B, Chacinska A. Mitochondrial stress-dependent regulation of cellular protein synthesis. J Cell Sci 2019; 132:132/8/jcs226258. [DOI: 10.1242/jcs.226258] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
ABSTRACT
The production of newly synthesized proteins is vital for all cellular functions and is a determinant of cell growth and proliferation. The synthesis of polypeptide chains from mRNA molecules requires sophisticated machineries and mechanisms that need to be tightly regulated, and adjustable to current needs of the cell. Failures in the regulation of translation contribute to the loss of protein homeostasis, which can have deleterious effects on cellular function and organismal health. Unsurprisingly, the regulation of translation appears to be a crucial element in stress response mechanisms. This review provides an overview of mechanisms that modulate cytosolic protein synthesis upon cellular stress, with a focus on the attenuation of translation in response to mitochondrial stress. We then highlight links between mitochondrion-derived reactive oxygen species and the attenuation of reversible cytosolic translation through the oxidation of ribosomal proteins at their cysteine residues. We also discuss emerging concepts of how cellular mechanisms to stress are adapted, including the existence of alternative ribosomes and stress granules, and the regulation of co-translational import upon organelle stress.
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Affiliation(s)
- Ulrike Topf
- Centre of New Technologies, University of Warsaw, Banacha 2C, Warsaw 02-097, Poland
- Department of Genetics, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5a, Warsaw 02-106, Poland
| | | | - Agnieszka Chacinska
- Centre of New Technologies, University of Warsaw, Banacha 2C, Warsaw 02-097, Poland
- ReMedy International Research Agenda Unit, University of Warsaw, Banacha 2C, Warsaw 02-097, Poland
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227
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Doan KN, Ellenrieder L, Becker T. Mitochondrial porin links protein biogenesis to metabolism. Curr Genet 2019; 65:899-903. [PMID: 30944955 DOI: 10.1007/s00294-019-00965-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 03/29/2019] [Accepted: 03/30/2019] [Indexed: 12/18/2022]
Abstract
In this report, we summarize recent findings about a role of the outer membrane metabolite channel VDAC/porin in protein import into mitochondria. Mitochondria fulfill key functions for cellular energy metabolism. Their biogenesis involves the import of about 1000 different proteins that are produced as precursors on cytosolic ribosomes. The translocase of the outer membrane (TOM complex) forms the entry gate for mitochondrial precursor proteins. Dedicated protein translocases sort the preproteins into the different mitochondrial subcompartments. While protein transport pathways are analyzed to some detail, only little is known about regulatory mechanisms that fine-tune protein import upon metabolic signaling. Recently, a dual role of the voltage-dependent anion channel (VDAC), also termed porin, in mitochondrial protein biogenesis was reported. First, VDAC/porin promotes as a coupling factor import of carrier proteins into the inner membrane. Second, VDAC/porin regulates the formation of the TOM complex. Thus, the major metabolite channel in the outer membrane VDAC/porin connects protein import to mitochondrial metabolism.
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Affiliation(s)
- Kim Nguyen Doan
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.,Faculty of Biology, University of Freiburg, 79104, Freiburg, Germany
| | - Lars Ellenrieder
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.,Kelly Services AG Providing Services To Novartis Pharma AG, 4058, Basel, Switzerland
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany. .,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany.
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228
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Kam A, Loo S, Dutta B, Sze SK, Tam JP. Plant-derived mitochondria-targeting cysteine-rich peptide modulates cellular bioenergetics. J Biol Chem 2019; 294:4000-4011. [PMID: 30674551 PMCID: PMC6422099 DOI: 10.1074/jbc.ra118.006693] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/07/2019] [Indexed: 12/16/2022] Open
Abstract
Mitochondria are attractive therapeutic targets for developing agents to delay age-related frailty and diseases. However, few promising leads have been identified from natural products. Previously, we identified roseltide rT1, a hyperstable 27-residue cysteine-rich peptide from Hibiscus sabdariffa, as a knottin-type neutrophil elastase inhibitor. Here, we show that roseltide rT1 is also a cell-penetrating, mitochondria-targeting peptide that increases ATP production. Results from flow cytometry, live-cell imaging, pulldown assays, and genetically-modified cell lines supported that roseltide rT1 enters cells via glycosaminoglycan-dependent endocytosis, and enters the mitochondria through TOM20, a mitochondrial protein import receptor. We further showed that roseltide rT1 increases cellular ATP production via mitochondrial membrane hyperpolarization. Using biotinylated roseltide rT1 for target identification and proteomic analysis, we showed that human mitochondrial membrane ATP synthase subunit O is an intramitochondrial target. Collectively, these data support our discovery that roseltide rT1 is a first-in-class mitochondria-targeting, cysteine-rich peptide with potentials to be developed into tools to further our understanding of mitochrondria-related diseases.
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Affiliation(s)
- Antony Kam
- From the School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Shining Loo
- From the School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Bamaprasad Dutta
- From the School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Siu Kwan Sze
- From the School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - James P Tam
- From the School of Biological Sciences, Nanyang Technological University, 637551 Singapore
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229
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Ellenrieder L, Dieterle MP, Doan KN, Mårtensson CU, Floerchinger A, Campo ML, Pfanner N, Becker T. Dual Role of Mitochondrial Porin in Metabolite Transport across the Outer Membrane and Protein Transfer to the Inner Membrane. Mol Cell 2019; 73:1056-1065.e7. [DOI: 10.1016/j.molcel.2018.12.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 11/09/2018] [Accepted: 12/14/2018] [Indexed: 01/26/2023]
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230
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Hwang SH, Kim MC, Ji S, Yang Y, Jeong Y, Kim Y. Glucose starvation induces resistance to metformin through the elevation of mitochondrial multidrug resistance protein 1. Cancer Sci 2019; 110:1256-1267. [PMID: 30689265 PMCID: PMC6447852 DOI: 10.1111/cas.13952] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/20/2022] Open
Abstract
Metformin, a drug for type 2 diabetes mellitus, has shown therapeutic effects for various cancers. However, it had no beneficial effects on the survival rate of human malignant mesothelioma (HMM) patients. The present study was performed to elucidate the underlying mechanism of metformin resistance in HMM cells. Glucose‐starved HMM cells had enhanced resistance to metformin, demonstrated by decreased apoptosis and autophagy and increased cell survival. These cells showed abnormalities in mitochondria, such as decreased ATP synthesis, morphological elongation, altered mitochondrial permeability transition pore and hyperpolarization of mitochondrial membrane potential (MMP). Intriguingly, Mdr1 was significantly upregulated in mitochondria but not in cell membrane. The upregulated mitochondrial Mdr1 was reversed by treatment with carbonyl cyanide m‐chlorophenyl hydrazone, an MMP depolarization inducer. Furthermore, apoptosis and autophagy were increased in multidrug resistance protein 1 knockout HMM cells cultured under glucose starvation with metformin treatment. The data suggest that mitochondrial Mdr1 plays a critical role in the chemoresistance to metformin in HMM cells, which could be a potential target for improving its therapeutic efficacy.
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Affiliation(s)
- Sung-Hyun Hwang
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Myung-Chul Kim
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Sumin Ji
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Yeseul Yang
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Yeji Jeong
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,BK21 PLUS Program for Creative Veterinary Science Research, College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Yongbaek Kim
- Laboratory of Veterinary Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.,Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Korea
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231
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Mitochondrial presequence import: Multiple regulatory knobs fine-tune mitochondrial biogenesis and homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2019; 1866:930-944. [PMID: 30802482 DOI: 10.1016/j.bbamcr.2019.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 02/14/2019] [Accepted: 02/19/2019] [Indexed: 12/22/2022]
Abstract
Mitochondria are pivotal organelles for cellular signaling and metabolism, and their dysfunction leads to severe cellular stress. About 60-70% of the mitochondrial proteome consists of preproteins synthesized in the cytosol with an amino-terminal cleavable presequence targeting signal. The TIM23 complex transports presequence signals towards the mitochondrial matrix. Ultimately, the mature protein segments are either transported into the matrix or sorted to the inner membrane. To ensure accurate preprotein import into distinct mitochondrial sub-compartments, the TIM23 machinery adopts specific functional conformations and interacts with different partner complexes. Regulatory subunits modulate the translocase dynamics, tailoring the import reaction to the incoming preprotein. The mitochondrial membrane potential and the ATP generated via oxidative phosphorylation are key energy sources in driving the presequence import pathway. Thus, mitochondrial dysfunctions have rapid repercussions on biogenesis. Cellular mechanisms exploit the presequence import pathway to monitor mitochondrial dysfunctions and mount transcriptional and proteostatic responses to restore functionality.
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232
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Geng J, Wei M, Yuan X, Liu Z, Wang X, Zhang D, Luo L, Wu J, Guo W, Qin ZH. TIGAR regulates mitochondrial functions through SIRT1-PGC1α pathway and translocation of TIGAR into mitochondria in skeletal muscle. FASEB J 2019; 33:6082-6098. [PMID: 30726106 DOI: 10.1096/fj.201802209r] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
TP53-induced glycolysis and apoptosis regulator (TIGAR), a glycolytic inhibitor, plays vital roles in regulating cellular metabolism and oxidative stress. However, the role of highly expressed TIGAR in skeletal muscle remains unexplored. In the present study, TIGAR levels varied in different skeletal muscles and fibers. An exhaustive swimming test with a load corresponding to 5% of body weight was utilized in mice to assess the effects of TIGAR on exercise-induced fatigue and muscle damage. The running time and metabolic indicators were significantly greater in wild-type (WT) mice compared with TIGAR knockout (KO) mice. Poor exercise capacity was accompanied by decreased type IIA fibers in TIGAR KO mice. Decreased mitochondrial number and mitochondrial oxidative phosphorylation were observed more in TIGAR KO mice than in WT mice, which were involved in sirtuin 1 (SIRT1)-mediated deacetylation of peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α), and resveratrol treatment in TIGAR KO mice can increase mitochondrial content and exercise time. Much more TIGAR was also detected in mitochondria during exhaustive exercise. In addition, TIGAR, rather than mitochondria-targeted TIGAR achieved by in vitro plasmid transfection, promoted SIRT1-PGC1α pathway. Glutathione S-transferase-TIGAR pull-down assay followed by liquid chromatography mass spectrometry found that TIGAR interacted with ATP synthase F1 subunit α (ATP5A1), and its binding to ATP5A1 increased during exhaustive exercise. Overexpression of mitochondrial-TIGAR enhanced ATP generation, maintained mitochondrial membrane potential and reduced mitochondrial oxidative stress under hypoxia condition. Taken together, our results uncovered a novel role for TIGAR in mitochondrial regulation in fast-twitch oxidative skeletal muscle through SIRT1-PGC1α and translocation into mitochondria, which contribute to the increase in exercise endurance of mice.-Geng, J., Wei, M., Yuan, X., Liu, Z., Wang, X., Zhang, D., Luo, L., Wu, J., Guo, W., Qin, Z.-H. TIGAR regulates mitochondrial functions through SIRT1-PGC1α pathway and translocation of TIGAR into mitochondria in skeletal muscle.
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Affiliation(s)
- Ji Geng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Mingzhen Wei
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Xiao Yuan
- Pathology Department, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Ziqi Liu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Xinxin Wang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Dingmei Zhang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Li Luo
- School of Physical Education and Sports Science, Soochow University, Suzhou, China
| | - Junchao Wu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Wenjie Guo
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, School of Pharmaceutical Sciences, Soochow University, Suzhou, China
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233
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Meyer AJ, Riemer J, Rouhier N. Oxidative protein folding: state-of-the-art and current avenues of research in plants. THE NEW PHYTOLOGIST 2019; 221:1230-1246. [PMID: 30230547 DOI: 10.1111/nph.15436] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Accepted: 08/01/2018] [Indexed: 06/08/2023]
Abstract
Contents Summary 1230 I. Introduction 1230 II. Formation and isomerization of disulfides in the ER and the Golgi apparatus 1231 III. The disulfide relay in the mitochondrial intermembrane space: why are plants different? 1236 IV. Disulfide bond formation on luminal proteins in thylakoids 1240 V. Conclusion 1242 Acknowledgements 1242 References 1242 SUMMARY: Disulfide bonds are post-translational modifications crucial for the structure and function of thousands of proteins. Their formation and isomerization, referred to as oxidative folding, require specific protein machineries found in oxidizing subcellular compartments, namely the endoplasmic reticulum and the associated endomembrane system, the intermembrane space of mitochondria and the thylakoid lumen of chloroplasts. At least one protein component is required for transferring electrons from substrate proteins to an acceptor that is usually molecular oxygen. For oxidation reactions, incoming reduced substrates are oxidized by thiol-oxidoreductase proteins (or domains in case of chimeric proteins), which are usually themselves oxidized by a single thiol oxidase, the enzyme generating disulfide bonds de novo. By contrast, the description of the molecular actors and pathways involved in proofreading and isomerization of misfolded proteins, which require a tightly controlled redox balance, lags behind. Herein we provide a general overview of the knowledge acquired on the systems responsible for oxidative protein folding in photosynthetic organisms, highlighting their particularities compared to other eukaryotes. Current research challenges are discussed including the importance and specificity of these oxidation systems in the context of the existence of reducing systems in the same compartments.
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Affiliation(s)
- Andreas J Meyer
- INRES-Chemical Signalling, University of Bonn, 53113, Bonn, Germany
| | - Jan Riemer
- Institute of Biochemistry, University of Cologne, 50674, Cologne, Germany
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234
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Identification and characterization of signal peptide of Mitofusin1 (Mfn1). Biochem Biophys Res Commun 2019; 509:707-712. [DOI: 10.1016/j.bbrc.2018.12.165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 12/26/2018] [Indexed: 01/24/2023]
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235
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Chai YL, Xing H, Chong JR, Francis PT, Ballard CG, Chen CP, Lai MKP. Mitochondrial Translocase of the Outer Membrane Alterations May Underlie Dysfunctional Oxidative Phosphorylation in Alzheimer's Disease. J Alzheimers Dis 2019; 61:793-801. [PMID: 29254089 DOI: 10.3233/jad-170613] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The translocase of the outer membrane (TOM) is a vital mitochondrial transport system facilitating the importation of nuclear encoded proteins into the organelle. While mitochondrial dysfunction, including perturbation of oxidative phosphorylation (OXPHOS) complex, is evident in Alzheimer's disease (AD), it remains unclear whether the observed OXPHOS deficits may be associated with TOM alterations. OBJECTIVES To correlate TOM subunits with OXPHOS complex proteins in AD. METHODS Postmortem neocortex (BA40) from AD and age-matched controls were processed to obtain mitochondrial enriched homogenates for the measurement of Tom20, Tom22, Tom40, and Tom70 as well as components of OXPHOS complex I-V by immunoblotting. RESULTS Tom20 and Tom70 immunoreactivities were significantly reduced in AD, as were components of OXPHOS complex I and III. Both Tom20 and Tom70 positively correlated with complex III and V, while Tom20 also correlated withcomplex IV. CONCLUSION Reductions in certain TOM subunits and their correlations with specific OXPHOS complex proteins suggest that an impaired mitochondrial transportation system may contribute to previously observed oxidative phosphorylation deficits in AD. Follow-up studies are needed to corroborate the present correlative study.
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Affiliation(s)
- Yuek Ling Chai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Huayang Xing
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Joyce R Chong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Paul T Francis
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Clive G Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK.,University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Wolfson Centre for Age-Related Diseases, King's College London, London, UK
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236
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Singh R, Goyal VD, Kumar A, Sabharwal NS, Makde RD. Crystal structures and biochemical analyses of intermediate cleavage peptidase: role of dynamics in enzymatic function. FEBS Lett 2019; 593:443-454. [PMID: 30582634 DOI: 10.1002/1873-3468.13321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/19/2018] [Accepted: 12/19/2018] [Indexed: 01/20/2023]
Abstract
Intermediate cleavage peptidase (Icp55) processes a subset of mitochondrial matrix proteins by removing a bulky residue at their N termini, leaving behind smaller N-terminal residues (icp activity). This contributes towards the stability of the mitochondrial proteome. We report crystal structures of yeast Icp55 including one bound to the apstatin inhibitor. Apart from icp activity, the enzyme was found to exhibit Xaa-Pro aminopeptidase activity in vitro. Structural and biochemical data suggest that the enzyme exists in a rapid equilibrium between monomer and dimer. Furthermore, the dimer, and not the monomer, was found to be the active species with loop dynamics at the dimer interface playing an important role in activity. Based on the new evidence, we propose a model for binding and processing of cellular targets by Icp55. DATABASE: The atomic coordinates and structure factors for the structures of Icp55 (code 6A9T, 6A9U, 6A9V) have been deposited in the Protein Data Bank (PDB) (http://www.pdb.org/).
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Affiliation(s)
- Rahul Singh
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Venuka Durani Goyal
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Ashwani Kumar
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Naripjeet Singh Sabharwal
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Ravindra D Makde
- High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Mumbai, India
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237
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Strangers in strange lands: mitochondrial proteins found at extra-mitochondrial locations. Biochem J 2019; 476:25-37. [DOI: 10.1042/bcj20180473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 11/23/2018] [Accepted: 11/27/2018] [Indexed: 12/18/2022]
Abstract
Abstract
The mitochondrial proteome is estimated to contain ∼1100 proteins, the vast majority of which are nuclear-encoded, with only 13 proteins encoded by the mitochondrial genome. The import of these nuclear-encoded proteins into mitochondria was widely believed to be unidirectional, but recent discoveries have revealed that many these ‘mitochondrial’ proteins are exported, and have extra-mitochondrial activities divergent from their mitochondrial function. Surprisingly, three of the exported proteins discovered thus far are mitochondrially encoded and have significantly different extra-mitochondrial roles than those performed within the mitochondrion. In this review, we will detail the wide variety of proteins once thought to only reside within mitochondria, but now known to ‘emigrate’ from mitochondria in order to attain ‘dual citizenship’, present both within mitochondria and elsewhere.
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238
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Richter F, Dennerlein S, Nikolov M, Jans DC, Naumenko N, Aich A, MacVicar T, Linden A, Jakobs S, Urlaub H, Langer T, Rehling P. ROMO1 is a constituent of the human presequence translocase required for YME1L protease import. J Cell Biol 2018; 218:598-614. [PMID: 30598479 PMCID: PMC6363466 DOI: 10.1083/jcb.201806093] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/18/2018] [Accepted: 11/26/2018] [Indexed: 01/15/2023] Open
Abstract
Mitochondria are the powerhouses of eukaryotic cells and rely on protein import from the cytosol. Richter et al. found ROMO1 as a new constituent of the human mitochondrial import machinery linking protein import to quality control and mitochondrial morphology. The mitochondrial presequence translocation machinery (TIM23 complex) is conserved between the yeast Saccharomyces cerevisiae and humans; however, functional characterization has been mainly performed in yeast. Here, we define the constituents of the human TIM23 complex using mass spectrometry and identified ROMO1 as a new translocase constituent with an exceptionally short half-life. Analyses of a ROMO1 knockout cell line revealed aberrant inner membrane structure and altered processing of the GTPase OPA1. We show that in the absence of ROMO1, mitochondria lose the inner membrane YME1L protease, which participates in OPA1 processing and ROMO1 turnover. While ROMO1 is dispensable for general protein import along the presequence pathway, we show that it participates in the dynamics of TIM21 during respiratory chain biogenesis and is specifically required for import of YME1L. This selective import defect can be linked to charge distribution in the unusually long targeting sequence of YME1L. Our analyses establish an unexpected link between mitochondrial protein import and inner membrane protein quality control.
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Affiliation(s)
- Frank Richter
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Sven Dennerlein
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Miroslav Nikolov
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Daniel C Jans
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Neurology, University Medical Center, Göttingen, Germany
| | - Nataliia Naumenko
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas MacVicar
- Department of Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Andreas Linden
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Stefan Jakobs
- Department of NanoBiophotonics, Mitochondrial Structure and Dynamics Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Department of Neurology, University Medical Center, Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Group, Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Thomas Langer
- Department of Mitochondrial Proteostasis, Max Planck Institute for Biology of Ageing, Cologne, Germany
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, Germany .,Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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239
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Xi J, Li M, Jing B, An M, Yu C, Pinnock CB, Zhu Y, Lam MT, Liu H. Long-Circulating Amphiphilic Doxorubicin for Tumor Mitochondria-Specific Targeting. ACS APPLIED MATERIALS & INTERFACES 2018; 10:43482-43492. [PMID: 30479120 PMCID: PMC6893847 DOI: 10.1021/acsami.8b17399] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The mitochondria have emerged as a novel target for cancer chemotherapy primarily due to their central roles in energy metabolism and apoptosis regulation. Here, we report a new molecular approach to achieve high levels of tumor- and mitochondria-selective deliveries of the anticancer drug doxorubicin. This is achieved by molecular engineering, which functionalizes doxorubicin with a hydrophobic lipid tail conjugated by a solubility-promoting poly(ethylene glycol) polymer (amphiphilic doxorubicin or amph-DOX). In vivo, the amphiphile conjugated to doxorubicin exhibits a dual function: (i) it binds avidly to serum albumin and hijacks albumin's circulating and transporting pathways, resulting in prolonged circulation in blood, increased accumulation in tumor, and reduced exposure to the heart; (ii) it also redirects doxorubicin to mitochondria by altering the drug molecule's intracellular sorting and transportation routes. Efficient mitochondrial targeting with amph-DOX causes a significant increase of reactive oxygen species levels in tumor cells, resulting in markedly improved antitumor efficacy than the unmodified doxorubicin. Amphiphilic modification provides a simple strategy to simultaneously increase the efficacy and safety of doxorubicin in cancer chemotherapy.
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Affiliation(s)
- Jingchao Xi
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Meng Li
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Benxin Jing
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Myunggi An
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Chunsong Yu
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Cameron B. Pinnock
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan 48202, United States
| | - Yingxi Zhu
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
| | - Mai T. Lam
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan 48202, United States
| | - Haipeng Liu
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, United States
- Department of Oncology, Wayne State University, Detroit, Michigan 48201, United States
- Tumor Biology and Microenvironment Program, Barbara Ann Karmanos Cancer Institute, Detroit, Michigan 48201, United States
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240
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Inner Mitochondrial Translocase Tim50 Is Central in Adrenal and Testicular Steroid Synthesis. Mol Cell Biol 2018; 39:MCB.00484-18. [PMID: 30348838 DOI: 10.1128/mcb.00484-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 10/14/2018] [Indexed: 01/24/2023] Open
Abstract
Adrenal and gonadal mitochondrial metabolic activity requires electrons from cofactors, cholesterol, and a substrate for rapid steroid synthesis, an essential requirement for mammalian survival. Substrate activity depends on its environment, which is regulated by chaperones and mitochondrial translocases. Cytochrome P450 side-chain cleavage enzyme (SCC or CYP11A1) catalyzes cholesterol to pregnenolone conversion, although its mechanism of action is not well understood. We find that SCC is directly imported into the mitochondrial matrix, where its N-terminal sequence is cleaved sequentially, after which it becomes activated following the second cleavage, which is dependent on the folding of the protein. Following integration of the SCC C terminus into the TIM23 complex, amino acids 141 to 146 interact with the intermembrane-exposed Tim50 protein, forming a large complex. The absence of Tim50 or its mutation reduced enzymatic activity. For the first time, we report that a protein activated at the matrix remains mostly unfolded and is transported back to the IMS to integrate with the TIM23 translocase complex and align with the Tim50 protein. Amino acid changes that suppress the association of Tim50 with SCC ablate metabolic activity. Thus, the TIM23 complex is the central regulator of metabolism guided by Tim50.
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241
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Li J, Kolberg K, Schlecht U, St Onge RP, Aparicio AM, Horecka J, Davis RW, Hillenmeyer ME, Harvey CJB. A biosensor-based approach reveals links between efflux pump expression and cell cycle regulation in pleiotropic drug resistance of yeast. J Biol Chem 2018; 294:1257-1266. [PMID: 30514758 DOI: 10.1074/jbc.ra118.003904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 10/19/2018] [Indexed: 11/06/2022] Open
Abstract
Multidrug resistance is highly conserved in mammalian, fungal, and bacterial cells, is characterized by resistance to several unrelated xenobiotics, and poses significant challenges to managing infections and many cancers. Eukaryotes use a highly conserved set of drug efflux transporters that confer pleiotropic drug resistance (PDR). To interrogate the regulation of this critical process, here we developed a small molecule-responsive biosensor that couples transcriptional induction of PDR genes to growth rate in the yeast Saccharomyces cerevisiae Using diverse PDR inducers and the homozygous diploid deletion collection, we applied this biosensor system to genome-wide screens for potential PDR regulators. In addition to recapitulating the activity of previously known factors, these screens identified a series of genes involved in a variety of cellular processes with significant but previously uncharacterized roles in the modulation of yeast PDR. Genes identified as down-regulators of the PDR included those encoding the MAD family of proteins involved in the mitotic spindle assembly checkpoint (SAC) complex. Of note, we demonstrated that genetic disruptions of the mitotic spindle assembly checkpoint elevate expression of PDR-mediating efflux pumps in response to exposure to a variety of compounds that themselves have no known influence on the cell cycle. These results not only establish our biosensor system as a viable tool for investigating PDR in a high-throughput fashion, but also uncover critical control mechanisms governing the PDR response and a previously uncharacterized link between PDR and cell cycle regulation in yeast.
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Affiliation(s)
- Jian Li
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Kristen Kolberg
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Ulrich Schlecht
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Robert P St Onge
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Ana Maria Aparicio
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Joe Horecka
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Ronald W Davis
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Maureen E Hillenmeyer
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304
| | - Colin J B Harvey
- Department of Biochemistry, Stanford Genome Technology Center, Stanford University School of Medicine, Palo Alto, California 94304.
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Pacheu-Grau D, Callegari S, Emperador S, Thompson K, Aich A, Topol SE, Spencer EG, McFarland R, Ruiz-Pesini E, Torkamani A, Taylor RW, Montoya J, Rehling P. Mutations of the mitochondrial carrier translocase channel subunit TIM22 cause early-onset mitochondrial myopathy. Hum Mol Genet 2018; 27:4135-4144. [PMID: 30452684 PMCID: PMC6240735 DOI: 10.1093/hmg/ddy305] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 08/10/2018] [Accepted: 08/10/2018] [Indexed: 11/13/2022] Open
Abstract
Protein import into mitochondria is facilitated by translocases within the outer and the inner mitochondrial membranes that are dedicated to a highly specific subset of client proteins. The mitochondrial carrier translocase (TIM22 complex) inserts multispanning proteins, such as mitochondrial metabolite carriers and translocase subunits (TIM23, TIM17A/B and TIM22), into the inner mitochondrial membrane. Both types of substrates are essential for mitochondrial metabolic function and biogenesis. Here, we report on a subject, diagnosed at 1.5 years, with a neuromuscular presentation, comprising hypotonia, gastroesophageal reflux disease and persistently elevated serum and Cerebrospinal fluid lactate (CSF). Patient fibroblasts displayed reduced oxidative capacity and altered mitochondrial morphology. Using trans-mitochondrial cybrid cell lines, we excluded a candidate variant in mitochondrial DNA as causative of these effects. Whole-exome sequencing identified compound heterozygous variants in the TIM22 gene (NM_013337), resulting in premature truncation in one allele (p.Tyr25Ter) and a point mutation in a conserved residue (p.Val33Leu), within the intermembrane space region, of the TIM22 protein in the second allele. Although mRNA transcripts of TIM22 were elevated, biochemical analyses revealed lower levels of TIM22 protein and an even greater deficiency of TIM22 complex formation. In agreement with a defect in carrier translocase function, carrier protein amounts in the inner membrane were found to be reduced. This is the first report of pathogenic variants in the TIM22 pore-forming subunit of the carrier translocase affecting the biogenesis of inner mitochondrial membrane proteins critical for metabolite exchange.
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Affiliation(s)
- David Pacheu-Grau
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, D-37073, Germany
| | - Sylvie Callegari
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, D-37073, Germany
| | - Sonia Emperador
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza-CIBER de Enfermedades Raras (CIBERER)-Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, 50013, Spain
| | - Kyle Thompson
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Abhishek Aich
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, D-37073, Germany
| | - Sarah E Topol
- The Scripps Translational Science Institute, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Emily G Spencer
- The Scripps Translational Science Institute, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Eduardo Ruiz-Pesini
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza-CIBER de Enfermedades Raras (CIBERER)-Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, 50013, Spain
| | - Ali Torkamani
- The Scripps Translational Science Institute, The Scripps Research Institute, La Jolla, CA 92037, United States
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, United States
| | - Robert W Taylor
- Wellcome Centre for Mitochondrial Research, Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Julio Montoya
- Departamento de Bioquímica y Biología Molecular y Celular, Universidad de Zaragoza-CIBER de Enfermedades Raras (CIBERER)-Instituto de Investigación Sanitaria de Aragón (IIS Aragón), Zaragoza, 50013, Spain
| | - Peter Rehling
- Department of Cellular Biochemistry, University Medical Center Göttingen, Göttingen, D-37073, Germany
- Max-Planck Institute for Biophysical Chemistry, D-37077, Göttingen, Germany
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243
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Jády BE, Ketele A, Kiss T. Dynamic association of human mRNP proteins with mitochondrial tRNAs in the cytosol. RNA (NEW YORK, N.Y.) 2018; 24:1706-1720. [PMID: 30139801 PMCID: PMC6239184 DOI: 10.1261/rna.066738.118] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 07/29/2018] [Indexed: 05/12/2023]
Abstract
Cytoplasmic localization, stability, and translation of mRNAs are controlled by their dynamic association of numerous mRNA-binding (mRNP) proteins, including cold shock domain (CSD)-containing proteins, heterogeneous nuclear ribonucleoproteins (hnRNPs), and serine/arginine-rich (SR) proteins. Here, we demonstrate that the most abundant human mRNP protein, the CSD-containing Y-box-binding protein 1 (YBX1), the closely related YBX3 protein, and other mRNP proteins, such as SRSF1, SRSF2, SRSF3, hnRNP A1, and H, specifically and efficiently interact with overlapping sets of mitochondrial tRNAs (mt tRNAs). In vitro reconstitution and in vivo binding experiments show that YBX1 recognizes the D- and/or T-stem-loop regions of mt tRNAs through relying on the RNA-binding capacity of its CSD. Cell fractionation and in vivo RNA-protein cross-linking experiments demonstrate that YBX1 and YBX3 interact with mt tRNAs in the cytosol outside of mitochondria. Cell fractionation and fluorescence in situ hybridization experiments provide evidence that mitochondrial autophagy promotes the release of mt tRNAs from the mitochondria into the cytoplasm. Association of mRNP proteins with mt tRNAs is highly dynamic; it is rapidly increased upon transcription inhibition and decreased during apoptosis. Although the cytoplasmic function of mt tRNAs remains elusive, their dynamic interactions with key mRNA-binding proteins may influence cytoplasmic mRNA stability and/or translation.
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Affiliation(s)
- Beáta E Jády
- Laboratoire de Biologie Moléculaire Eucaryote du CNRS, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex 9, France
| | - Amandine Ketele
- Laboratoire de Biologie Moléculaire Eucaryote du CNRS, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex 9, France
| | - Tamás Kiss
- Laboratoire de Biologie Moléculaire Eucaryote du CNRS, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 31062 Toulouse Cedex 9, France
- Biological Research Centre, Hungarian Academy of Sciences, Szeged, 6726 Hungary
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244
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Mitochondrial protein import in trypanosomatids: Variations on a theme or fundamentally different? PLoS Pathog 2018; 14:e1007351. [PMID: 30496284 PMCID: PMC6264148 DOI: 10.1371/journal.ppat.1007351] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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245
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Fernández-Higuero JÁ, Betancor-Fernández I, Mesa-Torres N, Muga A, Salido E, Pey AL. Structural and functional insights on the roles of molecular chaperones in the mistargeting and aggregation phenotypes associated with primary hyperoxaluria type I. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 114:119-152. [PMID: 30635080 DOI: 10.1016/bs.apcsb.2018.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To carry out their biological function in cells, proteins must be folded and targeted to the appropriate subcellular location. These processes are controlled by a vast collection of interacting proteins collectively known as the protein homeostasis network, in which molecular chaperones play a prominent role. Protein homeostasis can be impaired by inherited mutations leading to genetic diseases. In this chapter, we focus on a particular disease, primary hyperoxaluria type 1 (PH1), in which disease-associated mutations exacerbate protein aggregation in the cell and mistarget the peroxisomal alanine:glyoxylate aminotransferase (AGT) protein to mitochondria, in part due to native state destabilization and enhanced interaction with Hsp60, 70 and 90 chaperone systems. After a general introduction of molecular chaperones and PH1, we review our current knowledge on the structural and energetic features of PH1-causing mutants that lead to these particular pathogenic mechanisms. From this perspective, and in the context of the key role of molecular chaperones in PH1 pathogenesis, we present and discuss current and future perspectives for pharmacological treatments for this disease.
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Affiliation(s)
- José Ángel Fernández-Higuero
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Isabel Betancor-Fernández
- Centre for Biomedical Research on Rare Diseases (CIBERER), Hospital Universitario de Canarias, ITB, University of La Laguna, Tenerife, Spain
| | - Noel Mesa-Torres
- Department of Physical Chemistry, University of Granada, Granada, Spain
| | - Arturo Muga
- Biofisika Institute (CSIC, UPV/EHU) and Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Eduardo Salido
- Centre for Biomedical Research on Rare Diseases (CIBERER), Hospital Universitario de Canarias, ITB, University of La Laguna, Tenerife, Spain
| | - Angel L Pey
- Department of Physical Chemistry, University of Granada, Granada, Spain.
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246
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Nyakundi DO, Bentley SJ, Boshoff A. Hsp70 Escort Protein: More Than a Regulator of Mitochondrial Hsp70. CURR PROTEOMICS 2018. [DOI: 10.2174/1570164615666180713104919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Hsp70 members occupy a central role in proteostasis and are found in different eukaryotic
cellular compartments. The mitochondrial Hsp70/J-protein machinery performs multiple functions vital
for the proper functioning of the mitochondria, including forming part of the import motor that
transports proteins from the cytosol into the matrix and inner membrane, and subsequently folds these
proteins in the mitochondria. However, unlike other Hsp70s, mitochondrial Hsp70 (mtHsp70) has the
propensity to self-aggregate, accumulating as insoluble aggregates. The self-aggregation of mtHsp70 is
caused by both interdomain and intramolecular communication within the ATPase and linker domains.
Since mtHsp70 is unable to fold itself into an active conformation, it requires an Hsp70 escort protein
(Hep) to both inhibit self-aggregation and promote the correct folding. Hep1 orthologues are present in
the mitochondria of many eukaryotic cells but are absent in prokaryotes. Hep1 proteins are relatively
small and contain a highly conserved zinc-finger domain with one tetracysteine motif that is essential
for binding zinc ions and maintaining the function and solubility of the protein. The zinc-finger domain
lies towards the C-terminus of Hep1 proteins, with very little conservation outside of this domain.
Other than maintaining mtHsp70 in a functional state, Hep1 proteins play a variety of other roles in the
cell and have been proposed to function as both chaperones and co-chaperones. The cellular
localisation and some of the functions are often speculative and are not common to all Hep1 proteins
analysed to date.
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Affiliation(s)
- David O. Nyakundi
- Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa
| | - Stephen J. Bentley
- Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Grahamstown 6140, South Africa
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247
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Germany EM, Zahayko N, Huebsch ML, Fox JL, Prahlad V, Khalimonchuk O. The AAA ATPase Afg1 preserves mitochondrial fidelity and cellular health by maintaining mitochondrial matrix proteostasis. J Cell Sci 2018; 131:jcs.219956. [PMID: 30301782 DOI: 10.1242/jcs.219956] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 10/01/2018] [Indexed: 11/20/2022] Open
Abstract
Mitochondrial functions are critical for cellular physiology; therefore, several conserved mechanisms are in place to maintain the functional integrity of mitochondria. However, many of the molecular details and components involved in ensuring mitochondrial fidelity remain obscure. Here, we identify a novel role for the conserved mitochondrial AAA ATPase Afg1 in mediating mitochondrial protein homeostasis during aging and in response to various cellular challenges. Saccharomyces cerevisiae cells lacking functional Afg1 are hypersensitive to oxidative insults, unable to tolerate protein misfolding in the matrix compartment and exhibit progressive mitochondrial failure as they age. Loss of the Afg1 ortholog LACE-1 in Caenorhabditis elegans is associated with reduced lifespan, impeded oxidative stress tolerance, impaired mitochondrial proteostasis in the motor neuron circuitry and altered behavioral plasticity. Our results indicate that Afg1 is a novel protein quality control factor, which plays an important evolutionarily conserved role in mitochondrial surveillance, and cellular and organismal health.
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Affiliation(s)
- Edward M Germany
- Department of Biochemistry, Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
| | - Nataliya Zahayko
- Department of Biochemistry, Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA
| | - Mason L Huebsch
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA
| | - Jennifer L Fox
- Department of Chemistry and Biochemistry, College of Charleston, Charleston, SC 29424, USA
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain Initiative, University of Iowa, Iowa City, IA 52242, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry, Nebraska Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA .,Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198, USA
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248
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Sokol AM, Uszczynska-Ratajczak B, Collins MM, Bazala M, Topf U, Lundegaard PR, Sugunan S, Guenther S, Kuenne C, Graumann J, Chan SSL, Stainier DYR, Chacinska A. Loss of the Mia40a oxidoreductase leads to hepato-pancreatic insufficiency in zebrafish. PLoS Genet 2018; 14:e1007743. [PMID: 30457989 PMCID: PMC6245507 DOI: 10.1371/journal.pgen.1007743] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2018] [Accepted: 10/05/2018] [Indexed: 02/07/2023] Open
Abstract
Development and function of tissues and organs are powered by the activity of mitochondria. In humans, inherited genetic mutations that lead to progressive mitochondrial pathology often manifest during infancy and can lead to death, reflecting the indispensable nature of mitochondrial biogenesis and function. Here, we describe a zebrafish mutant for the gene mia40a (chchd4a), the life-essential homologue of the evolutionarily conserved Mia40 oxidoreductase which drives the biogenesis of cysteine-rich mitochondrial proteins. We report that mia40a mutant animals undergo progressive cellular respiration defects and develop enlarged mitochondria in skeletal muscles before their ultimate death at the larval stage. We generated a deep transcriptomic and proteomic resource that allowed us to identify abnormalities in the development and physiology of endodermal organs, in particular the liver and pancreas. We identify the acinar cells of the exocrine pancreas to be severely affected by mutations in the MIA pathway. Our data contribute to a better understanding of the molecular, cellular and organismal effects of mitochondrial deficiency, important for the accurate diagnosis and future treatment strategies of mitochondrial diseases. Mitochondrial pathologies which result from mutations in the nuclear DNA remain incurable and often lead to death. As mitochondria play various roles in cellular and tissue-specific contexts, the symptoms of mitochondrial pathologies can differ between patients. Thus, diagnosis and treatment of mitochondrial disorders remain challenging. To enhance this, the generation of new models that explore and define the consequences of mitochondria insufficiencies is of central importance. Here, we present a mia40a zebrafish mutant as a model for mitochondrial dysfunction, caused by an imbalance in mitochondrial protein biogenesis. This mutant shares characteristics with existing reports on mitochondria dysfunction, and has led us to identify novel phenotypes such as enlarged mitochondrial clusters in skeletal muscles. In addition, our transcriptomics and proteomics data contribute important findings to the existing knowledge on how faulty mitochondria impinge on vertebrate development in molecular, tissue and organ specific contexts.
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Affiliation(s)
- Anna M. Sokol
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
- * E-mail: (AMS); (AC)
| | | | - Michelle M. Collins
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Michal Bazala
- International Institute of Molecular and Cell Biology, Warsaw, Poland
| | - Ulrike Topf
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Pia R. Lundegaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sreedevi Sugunan
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
| | - Stefan Guenther
- Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Carsten Kuenne
- Bioinformatics and Deep Sequencing Platform, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Johannes Graumann
- Biomolecular Mass Spectrometry, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Sherine S. L. Chan
- Department of Drug Discovery and Biomedical Sciences, College of Pharmacy, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Didier Y. R. Stainier
- Department of Developmental Genetics, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Agnieszka Chacinska
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Centre of New Technologies, University of Warsaw, Warsaw, Poland
- * E-mail: (AMS); (AC)
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249
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Srivastava A, Tama F, Kohda D, Miyashita O. Computational investigation of the conformational dynamics in Tom20-mitochondrial presequence tethered complexes. Proteins 2018; 87:81-90. [DOI: 10.1002/prot.25625] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 10/03/2018] [Accepted: 10/16/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Arpita Srivastava
- Department of Physics; Graduate School of Science, Nagoya University; Nagoya Japan
| | - Florence Tama
- Department of Physics; Graduate School of Science, Nagoya University; Nagoya Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University; Nagoya Japan
- RIKEN Center for Computational Science; Kobe Japan
| | - Daisuke Kohda
- Division of Structural Biology; Medical Institute of Bioregulation, Kyushu University; Fukuoka Japan
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250
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Weinhäupl K, Lindau C, Hessel A, Wang Y, Schütze C, Jores T, Melchionda L, Schönfisch B, Kalbacher H, Bersch B, Rapaport D, Brennich M, Lindorff-Larsen K, Wiedemann N, Schanda P. Structural Basis of Membrane Protein Chaperoning through the Mitochondrial Intermembrane Space. Cell 2018; 175:1365-1379.e25. [PMID: 30445040 PMCID: PMC6242696 DOI: 10.1016/j.cell.2018.10.039] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 08/16/2018] [Accepted: 10/15/2018] [Indexed: 12/04/2022]
Abstract
The exchange of metabolites between the mitochondrial matrix and the cytosol depends on β-barrel channels in the outer membrane and α-helical carrier proteins in the inner membrane. The essential translocase of the inner membrane (TIM) chaperones escort these proteins through the intermembrane space, but the structural and mechanistic details remain elusive. We have used an integrated structural biology approach to reveal the functional principle of TIM chaperones. Multiple clamp-like binding sites hold the mitochondrial membrane proteins in a translocation-competent elongated form, thus mimicking characteristics of co-translational membrane insertion. The bound preprotein undergoes conformational dynamics within the chaperone binding clefts, pointing to a multitude of dynamic local binding events. Mutations in these binding sites cause cell death or growth defects associated with impairment of carrier and β-barrel protein biogenesis. Our work reveals how a single mitochondrial "transfer-chaperone" system is able to guide α-helical and β-barrel membrane proteins in a "nascent chain-like" conformation through a ribosome-free compartment.
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Affiliation(s)
- Katharina Weinhäupl
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Caroline Lindau
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Audrey Hessel
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Yong Wang
- Structural Biology and NMR Laboratory, the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Conny Schütze
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Tobias Jores
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Laura Melchionda
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Birgit Schönfisch
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Hubert Kalbacher
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Beate Bersch
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany
| | - Martha Brennich
- European Molecular Biology Laboratory, 38042 Grenoble, France
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, the Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany.
| | - Paul Schanda
- Institut de Biologie Structurale (IBS), Univ. Grenoble Alpes, CEA, CNRS, 71 Avenue des Martyrs, 38000 Grenoble, France.
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