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Valcarcel-Jimenez L, Frezza C. Fumarate hydratase (FH) and cancer: a paradigm of oncometabolism. Br J Cancer 2023; 129:1546-1557. [PMID: 37689804 PMCID: PMC10645937 DOI: 10.1038/s41416-023-02412-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/10/2023] [Accepted: 08/18/2023] [Indexed: 09/11/2023] Open
Abstract
Fumarate hydratase (FH) is an enzyme of the Tricarboxylic Acid (TCA) cycle whose mutations lead to hereditary and sporadic forms of cancer. Although more than twenty years have passed since its discovery as the leading cause of the cancer syndrome Hereditary leiomyomatosis and Renal Cell Carcinoma (HLRCC), it is still unclear how the loss of FH causes cancer in a tissue-specific manner and with such aggressive behaviour. It has been shown that FH loss, via the accumulation of FH substrate fumarate, activates a series of oncogenic cascades whose contribution to transformation is still under investigation. In this review, we will summarise these recent findings in an integrated fashion and put forward the case that understanding the biology of FH and how its mutations promote transformation will be vital to establish novel paradigms of oncometabolism.
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Affiliation(s)
- Lorea Valcarcel-Jimenez
- Department of Biochemistry and Molecular Biology, Faculty of Science and Technology, UPV/EHU, University of the Basque Country (UPV/EHU), Leioa, Bizkaia, Spain.
| | - Christian Frezza
- University of Cologne, Faculty of Mathematics and Natural Sciences, Institute of Genetics, Cluster of Excellence Cellular Stress Responses in Aging-associated Diseases (CECAD), Cologne, Germany.
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Cluster of Excellence Cellular Stress Responses in Aging-associated Diseases (CECAD), Cologne, Germany.
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2
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Gu H, Zhu Y, Yang J, Jiang R, Deng Y, Li A, Fang Y, Wu Q, Tu H, Chang H, Wen J, Jiang X. Liver-Inspired Polyetherketoneketone Scaffolds Simulate Regenerative Signals and Mobilize Anti-Inflammatory Reserves to Reprogram Macrophage Metabolism for Boosted Osteoporotic Osseointegration. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302136. [PMID: 37400369 PMCID: PMC10477864 DOI: 10.1002/advs.202302136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/21/2023] [Indexed: 07/05/2023]
Abstract
Tissue regeneration is regulated by morphological clues of implants in bone defect repair. Engineered morphology can boost regenerative biocascades that conquer challenges such as material bioinertness and pathological microenvironments. Herein, a correlation between the liver extracellular skeleton morphology and the regenerative signaling, namely hepatocyte growth factor receptor (MET), is found to explain the mystery of rapid liver regeneration. Inspired by this unique structure, a biomimetic morphology is prepared on polyetherketoneketone (PEKK) via femtosecond laser etching and sulfonation. The morphology reproduces MET signaling in macrophages, causing positive immunoregulation and optimized osteogenesis. Moreover, the morphological clue activates an anti-inflammatory reserve (arginase-2) to translocate retrogradely from mitochondria to the cytoplasm due to the difference in spatial binding of heat shock protein 70. This translocation enhances oxidative respiration and complex II activity, reprogramming the metabolism of energy and arginine. The importance of MET signaling and arginase-2 in the anti-inflammatory repair of biomimetic scaffolds is also verified via chemical inhibition and gene knockout. Altogether, this study not only provides a novel biomimetic scaffold for osteoporotic bone defect repair that can simulate regenerative signals, but also reveals the significance and feasibility of strategies to mobilize anti-inflammatory reserves in bone regeneration.
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Affiliation(s)
- Hao Gu
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Yuhui Zhu
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Jiawei Yang
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Ruixue Jiang
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Yuwei Deng
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Anshuo Li
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Yingjing Fang
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Qianju Wu
- Stomatological Hospital of Xiamen Medical CollegeXiamen Key Laboratory of Stomatological Disease Diagnosis and TreatmentXiamenFujian361008China
| | - Honghuan Tu
- State Key Laboratory of Advanced Optical Communication Systems and NetworksSchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai200240China
| | - Haishuang Chang
- Shanghai Institute of Precision MedicineShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineShanghai200125China
| | - Jin Wen
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
| | - Xinquan Jiang
- Department of ProsthodonticsShanghai Ninth People's HospitalShanghai Jiao Tong University School of MedicineCollege of StomatologyShanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai200125China
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Bittner E, Stehlik T, Freitag J. Sharing the wealth: The versatility of proteins targeted to peroxisomes and other organelles. Front Cell Dev Biol 2022; 10:934331. [PMID: 36225313 PMCID: PMC9549241 DOI: 10.3389/fcell.2022.934331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Peroxisomes are eukaryotic organelles with critical functions in cellular energy and lipid metabolism. Depending on the organism, cell type, and developmental stage, they are involved in numerous other metabolic and regulatory pathways. Many peroxisomal functions require factors also relevant to other cellular compartments. Here, we review proteins shared by peroxisomes and at least one different site within the cell. We discuss the mechanisms to achieve dual targeting, their regulation, and functional consequences. Characterization of dual targeting is fundamental to understand how peroxisomes are integrated into the metabolic and regulatory circuits of eukaryotic cells.
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Saatchi F, Kirchmaier AL. Tolerance of DNA Replication Stress Is Promoted by Fumarate Through Modulation of Histone Demethylation and Enhancement of Replicative Intermediate Processing in Saccharomyces cerevisiae. Genetics 2019; 212:631-654. [PMID: 31123043 PMCID: PMC6614904 DOI: 10.1534/genetics.119.302238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 05/07/2019] [Indexed: 12/28/2022] Open
Abstract
Fumarase is a well-characterized TCA cycle enzyme that catalyzes the reversible conversion of fumarate to malate. In mammals, fumarase acts as a tumor suppressor, and loss-of-function mutations in the FH gene in hereditary leiomyomatosis and renal cell cancer result in the accumulation of intracellular fumarate-an inhibitor of α-ketoglutarate-dependent dioxygenases. Fumarase promotes DNA repair by nonhomologous end joining in mammalian cells through interaction with the histone variant H2A.Z, and inhibition of KDM2B, a H3 K36-specific histone demethylase. Here, we report that Saccharomyces cerevisiae fumarase, Fum1p, acts as a response factor during DNA replication stress, and fumarate enhances survival of yeast lacking Htz1p (H2A.Z in mammals). We observed that exposure to DNA replication stress led to upregulation as well as nuclear enrichment of Fum1p, and raising levels of fumarate in cells via deletion of FUM1 or addition of exogenous fumarate suppressed the sensitivity to DNA replication stress of htz1Δ mutants. This suppression was independent of modulating nucleotide pool levels. Rather, our results are consistent with fumarate conferring resistance to DNA replication stress in htz1Δ mutants by inhibiting the H3 K4-specific histone demethylase Jhd2p, and increasing H3 K4 methylation. Although the timing of checkpoint activation and deactivation remained largely unaffected by fumarate, sensors and mediators of the DNA replication checkpoint were required for fumarate-dependent resistance to replication stress in the htz1Δ mutants. Together, our findings imply metabolic enzymes and metabolites aid in processing replicative intermediates by affecting chromatin modification states, thereby promoting genome integrity.
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Affiliation(s)
- Faeze Saatchi
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana 47907
| | - Ann L Kirchmaier
- Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana 47907
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana 47907
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Zhao Y, Li Y, Zhao D, Zhang H, Liu Y, Liao H, Zhang Y, Yan H. Fumarate hydratase-specific T cell response in Chinese patients with autoimmune hepatitis. Clin Res Hepatol Gastroenterol 2018; 42:339-346. [PMID: 29610041 DOI: 10.1016/j.clinre.2017.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 12/19/2017] [Indexed: 02/04/2023]
Abstract
PURPOSE Fumarate hydratase (FH) is expressed in the serum of patients with autoimmune hepatitis (AIH). The specific involvement of FH-specific T cell response is currently unknown. The aim of the study was to assess the frequency and clinical significance of FH-specific T cell response in AIH. METHODS This was a prospective study of 42 consecutive patients admitted to the clinical study center of autoimmune liver disease of our Hospital, Capital Medical University (China) between January 2011 and December 2014. PBMCs were collected and the FH-specific T cell response was detected by Elispot. Cytokines and antibody responses were assessed. RESULTS Among the 42 AIH patients, 57.1% showed a positive response to FH peptides. The difference in FH-specific T cell response frequency among AIH patients and control groups was significant (P<0.001). The FH peptides induced the secretion of CD4+ and CD8+ T cells. The FH-specific T cell response in patients with active disease was stronger than in those with remission (P=0.0283). FH-specific T cell response in patients with active disease showed a positive association with ALT (r=0.4712, P=0.0098) and AST (r=0.3924, P=0.0352) levels. The magnitude of the FH-specific T cell response correlated with the HAI score (r=0.7290, P=0.0047) and anti-FH titer (r=0.6457, P=0.0093). CONCLUSION FH-specific T cell response may be detected in the blood of patients with AIH and seems to be associated with AIH disease progression. FH-specific T cell response could be a pathogenic cause of AIH.
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Affiliation(s)
- Yan Zhao
- Center for clinical laboratory, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China
| | - Yanli Li
- Beijing University of Chinese Medicine Third Affiliated Hospital, Beijing, China
| | - Dantong Zhao
- Center for clinical laboratory, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China
| | - Haiping Zhang
- Center for clinical laboratory, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China
| | - Yanmin Liu
- Study Centre of Autoimmune liver disease, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China
| | - Huiyu Liao
- Study Centre of Autoimmune liver disease, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China
| | - Yonghong Zhang
- Interventional therapy center, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China.
| | - Huiping Yan
- Center for clinical laboratory, Beijing You'An Hospital, Capital Medical University, 100069 Beijing, China.
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Leshets M, Silas YBH, Lehming N, Pines O. Fumarase: From the TCA Cycle to DNA Damage Response and Tumor Suppression. Front Mol Biosci 2018; 5:68. [PMID: 30090811 PMCID: PMC6068284 DOI: 10.3389/fmolb.2018.00068] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 07/02/2018] [Indexed: 12/22/2022] Open
Abstract
Fumarase is an enzyme of the tricarboxylic acid (TCA) cycle in mitochondria, but in recent years, it has emerged as a participant in the response to DNA double strand breaks (DSBs) in the nucleus. In fact, this enzyme is dual-targeted and can be also readily detected in the mitochondrial and cytosolic/nuclear compartments of all the eukaryotic organisms examined. Intriguingly, this evolutionary conserved cytosolic population of fumarase, its enzymatic activity and the associated metabolite fumarate, are required for the cellular DNA damage response (DDR) to double-strand breaks. Here we review findings from yeast and human cells regarding how fumarase and fumarate may precisely participate in the DNA damage response. In yeast, cytosolic fumarase is involved in the homologous recombination (HR) repair pathway, through its function in the DSB resection process. One target of this regulation is the resection enzyme Sae2. In human cells, fumarase is involved in the non-homologous end joining (NHEJ) repair pathway. Fumarase is phosphorylated by the DNA-dependent protein kinase (DNA-PK) complex, which induces the recruitment of fumarase to the DSB and local generation of fumarate. Fumarate inhibits the lysine demethylase 2B (KDM2B), thereby facilitating the dimethylation of histone H3, which leads to the repair of the break by the NHEJ pathway. Finally, we discuss the question how fumarase may function as a tumor suppressor via its metabolite substrate fumarate. We offer a number of models which can explain an apparent contradiction regarding how fumarate absence/accumulation, as a function of subcellular location and stage can determine tumorigenesis. Fumarate, on the one hand, a positive regulator of genome stability (its absence supports genome instability and tumorigenesis) and, on the other hand, its accumulation drives angiogenesis and proliferation (thereby supporting tumor establishment).
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Affiliation(s)
- Michael Leshets
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Yardena B H Silas
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Norbert Lehming
- NUS-HUJ-CREATE Program and the Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Ophry Pines
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada (IMRIC), Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,NUS-HUJ-CREATE Program and the Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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7
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Leshets M, Ramamurthy D, Lisby M, Lehming N, Pines O. Fumarase is involved in DNA double-strand break resection through a functional interaction with Sae2. Curr Genet 2017; 64:697-712. [DOI: 10.1007/s00294-017-0786-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 11/19/2017] [Accepted: 11/22/2017] [Indexed: 11/28/2022]
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Singer E, Silas YB, Ben-Yehuda S, Pines O. Bacterial fumarase and L-malic acid are evolutionary ancient components of the DNA damage response. eLife 2017; 6:30927. [PMID: 29140245 PMCID: PMC5711358 DOI: 10.7554/elife.30927] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 11/07/2017] [Indexed: 12/31/2022] Open
Abstract
Fumarase is distributed between two compartments of the eukaryotic cell. The enzyme catalyses the reversible conversion of fumaric to L-malic acid in mitochondria as part of the tricarboxylic acid (TCA) cycle, and in the cytosol/nucleus as part of the DNA damage response (DDR). Here, we show that fumarase of the model prokaryote Bacillus subtilis (Fum-bc) is induced upon DNA damage, co-localized with the bacterial DNA and is required for the DDR. Fum-bc can substitute for both eukaryotic functions in yeast. Furthermore, we found that the fumarase-dependent intracellular signaling of the B. subtilis DDR is achieved via production of L-malic acid, which affects the translation of RecN, the first protein recruited to DNA damage sites. This study provides a different evolutionary scenario in which the dual function of the ancient prokaryotic fumarase, led to its subsequent distribution into different cellular compartments in eukaryotes. Living cells make an enzyme called fumarase. It converts a chemical called fumaric acid into L-malic acid. This is a crucial step in primary metabolism and aerobic respiration, the process of using oxygen to release energy for life. Yet it is not the only role that fumarase plays. In the cells of eukaryotes such as plants, animals and even baker’s yeast, aerobic respiration happens inside compartments called mitochondria. Yet fumarase is also found in the nucleus, which contains the cell’s genetic material. Inside the nucleus, this enzyme takes part in the DNA damage response that senses and repairs damage to the genetic code. Simpler organisms, like bacteria, do not have mitochondria or a nucleus. Instead, all their reactions take place inside the main space within the cell. The current model for the evolution of fumarase is that the enzyme evolved in an ancient bacterium for the production of energy. Then, in more complex organisms, becoming split between the mitochondria and the nucleus allowed it to take on a second role in the DNA damage response. Singer et al. now challenge that model, and show that fumarase takes part in DNA damage repair in bacteria too. Bacillus subtilis has one fumarase gene, known as fum-bc. Singer et al. showed that, without this gene, the bacteria do not grow well under conditions where they need to use aerobic respiration. But, the bacteria also became sensitive to DNA-damaging agents such as ionizing radiation or a chemical called methyl methanesulfonate. Singer et al. then expressed the bacterial fum-bc gene in baker’s yeast, Saccharomyces cerevisiae. This organism has mitochondria and a cell nucleus. With the yeast's own fumarase gene switched off, the bacterial fumarase was able to take on both roles – aerobic respiration and the DNA damage response. In bacteria grown with the DNA-damaging chemical, the level of fumarase started to rise. A fluorescent tag revealed that it also changed location, moving close to the bacteria’s DNA. As such, even in bacteria, fumarase has two roles. Further experiments showed that the L-malic acid made by fumarase affects the production of a protein called RecN, and it is this protein that triggers DNA repair. These findings shed new light on the evolution of fumarase, and suggest that its dual role evolved before its dual location in eukaryotes. The next step is to find out exactly how L-malic acid affects the production of RecN.
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Affiliation(s)
- Esti Singer
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Yardena Bh Silas
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel.,CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Sinapore
| | - Sigal Ben-Yehuda
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Ophry Pines
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel.,CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Sinapore
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Guitart AV, Panagopoulou TI, Villacreces A, Vukovic M, Sepulveda C, Allen L, Carter RN, van de Lagemaat LN, Morgan M, Giles P, Sas Z, Gonzalez MV, Lawson H, Paris J, Edwards-Hicks J, Schaak K, Subramani C, Gezer D, Armesilla-Diaz A, Wills J, Easterbrook A, Coman D, So CWE, O'Carroll D, Vernimmen D, Rodrigues NP, Pollard PJ, Morton NM, Finch A, Kranc KR. Fumarate hydratase is a critical metabolic regulator of hematopoietic stem cell functions. J Exp Med 2017; 214:719-735. [PMID: 28202494 PMCID: PMC5339674 DOI: 10.1084/jem.20161087] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/29/2016] [Accepted: 01/20/2017] [Indexed: 11/04/2022] Open
Abstract
Strict regulation of stem cell metabolism is essential for tissue functions and tumor suppression. In this study, we investigated the role of fumarate hydratase (Fh1), a key component of the mitochondrial tricarboxylic acid (TCA) cycle and cytosolic fumarate metabolism, in normal and leukemic hematopoiesis. Hematopoiesis-specific Fh1 deletion (resulting in endogenous fumarate accumulation and a genetic TCA cycle block reflected by decreased maximal mitochondrial respiration) caused lethal fetal liver hematopoietic defects and hematopoietic stem cell (HSC) failure. Reexpression of extramitochondrial Fh1 (which normalized fumarate levels but not maximal mitochondrial respiration) rescued these phenotypes, indicating the causal role of cellular fumarate accumulation. However, HSCs lacking mitochondrial Fh1 (which had normal fumarate levels but defective maximal mitochondrial respiration) failed to self-renew and displayed lymphoid differentiation defects. In contrast, leukemia-initiating cells lacking mitochondrial Fh1 efficiently propagated Meis1/Hoxa9-driven leukemia. Thus, we identify novel roles for fumarate metabolism in HSC maintenance and hematopoietic differentiation and reveal a differential requirement for mitochondrial Fh1 in normal hematopoiesis and leukemia propagation.
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Affiliation(s)
- Amelie V Guitart
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Theano I Panagopoulou
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Arnaud Villacreces
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Milica Vukovic
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Catarina Sepulveda
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Lewis Allen
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Roderick N Carter
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Louie N van de Lagemaat
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
- The Roslin Institute, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Marcos Morgan
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Peter Giles
- Wales Gene Park and Wales Cancer Research Centre, Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff CF10 3XQ, Wales, UK
| | - Zuzanna Sas
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Marta Vila Gonzalez
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Hannah Lawson
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Jasmin Paris
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Joy Edwards-Hicks
- Edinburgh Cancer Research UK Centre, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Katrin Schaak
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Chithra Subramani
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Deniz Gezer
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Alejandro Armesilla-Diaz
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Jimi Wills
- Edinburgh Cancer Research UK Centre, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Aaron Easterbrook
- Mater Children's Private Hospital Brisbane, South Brisbane, Queensland 4101, Australia
| | - David Coman
- Department of Metabolic Medicine, The Lady Cilento Children's Hospital, South Brisbane, Queensland 4101, Australia
| | - Chi Wai Eric So
- Department of Haematological Medicine, Division of Cancer Studies, King's College London, London WC2R 2LS, England, UK
| | - Donal O'Carroll
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Douglas Vernimmen
- The Roslin Institute, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Neil P Rodrigues
- The European Cancer Stem Cell Research Institute, School of Biosciences, Cardiff University, Cardiff CF10 3XQ, Wales, UK
| | - Patrick J Pollard
- Edinburgh Cancer Research UK Centre, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Nicholas M Morton
- Centre for Cardiovascular Science, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Andrew Finch
- Edinburgh Cancer Research UK Centre, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
| | - Kamil R Kranc
- Medical Research Council Centre for Regenerative Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
- Edinburgh Cancer Research UK Centre, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH8 9YL, Scotland, UK
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10
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Abstract
Local synthesis of proteins near their activity site has been demonstrated in many biological systems, and has diverse contributions to cellular functions. Studies in recent years have revealed that hundreds of mitochondria-destined proteins are synthesized by cytosolic ribosomes near the mitochondrial outer membrane, indicating that localized translation also occurs at this cellular locus. Furthermore, in the last year central factors that are involved in this process were identified in yeast, Drosophila, and human cells. Herein we review the experimental evidence for localized translation on the cytosolic side of the mitochondrial outer membrane; in addition, we describe the factors that are involved in this process and discuss the conservation of this mechanism among various species. We also describe the relationship between localized translation and import into the mitochondria and suggest avenues of study that look beyond cotranslational import. Finally we discuss future challenges in characterizing the mechanisms for localized translation and its physiological significance.
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Affiliation(s)
- Chen Lesnik
- a Department of Biology ; Technion - Israel Institute of Technology ; Haifa , Israel
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Hollinshead KER, Tennant DA. Mitochondrial metabolic remodeling in response to genetic and environmental perturbations. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2016; 8:272-85. [PMID: 27196610 PMCID: PMC4982039 DOI: 10.1002/wsbm.1334] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 01/26/2016] [Accepted: 01/29/2016] [Indexed: 01/10/2023]
Abstract
Mitochondria are metabolic hubs within mammalian cells and demonstrate significant metabolic plasticity. In oxygenated environments with ample carbohydrate, amino acid, and lipid sources, they are able to use the tricarboxylic acid cycle for the production of anabolic metabolites and ATP. However, in conditions where oxygen becomes limiting for oxidative phosphorylation, they can rapidly signal to increase cytosolic glycolytic ATP production, while awaiting hypoxia‐induced changes in the proteome mediated by the activity of transcription factors such as hypoxia‐inducible factor 1. Hypoxia is a well‐described phenotype of most cancers, driving many aspects of malignancy. Improving our understanding of how mitochondria change their metabolism in response to this stimulus may therefore elicit the design of new selective therapies. Many of the recent advances in our understanding of mitochondrial metabolic plasticity have been acquired through investigations of cancer‐associated mutations in metabolic enzymes, including succinate dehydrogenase, fumarate hydratase, and isocitrate dehydrogenase. This review will describe how metabolic perturbations induced by hypoxia and mutations in these enzymes have informed our knowledge in the control of mitochondrial metabolism, and will examine what this may mean for the biology of the cancers in which these mutations are observed. WIREs Syst Biol Med 2016, 8:272–285. doi: 10.1002/wsbm.1334 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Kate E R Hollinshead
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Daniel A Tennant
- Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
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Dik E, Naamati A, Asraf H, Lehming N, Pines O. Human Fumarate Hydratase Is Dual Localized by an Alternative Transcription Initiation Mechanism. Traffic 2016; 17:720-32. [DOI: 10.1111/tra.12397] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/29/2016] [Accepted: 03/29/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Ekaterina Dik
- Department of Microbiology Molecular Genetics, IMRIC, Faculty of Medicine; Hebrew University of Jerusalem; Jerusalem Israel
| | - Adi Naamati
- Department of Microbiology Molecular Genetics, IMRIC, Faculty of Medicine; Hebrew University of Jerusalem; Jerusalem Israel
| | - Hadar Asraf
- Department of Microbiology Molecular Genetics, IMRIC, Faculty of Medicine; Hebrew University of Jerusalem; Jerusalem Israel
| | - Norbert Lehming
- CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine; National University of Singapore; Singapore Singapore
| | - Ophry Pines
- Department of Microbiology Molecular Genetics, IMRIC, Faculty of Medicine; Hebrew University of Jerusalem; Jerusalem Israel
- CREATE-NUS-HUJ Program and the Department of Microbiology, Yong Loo Lin School of Medicine; National University of Singapore; Singapore Singapore
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A Perspective on Transport of Proteins into Mitochondria: A Myriad of Open Questions. J Mol Biol 2015; 427:1135-58. [DOI: 10.1016/j.jmb.2015.02.001] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/30/2015] [Accepted: 02/02/2015] [Indexed: 11/22/2022]
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Konieczna A, Szczepańska A, Sawiuk K, Łyżeń R, Węgrzyn G. Enzymes of the central carbon metabolism: Are they linkers between transcription, DNA replication, and carcinogenesis? Med Hypotheses 2015; 84:58-67. [DOI: 10.1016/j.mehy.2014.11.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 11/05/2014] [Accepted: 11/21/2014] [Indexed: 12/16/2022]
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Park K, Jung SJ, Kim H, Kim H. Mode of membrane insertion of individual transmembrane segments in Mdl1 and Mdl2, multi-spanning mitochondrial ABC transporters. FEBS Lett 2014; 588:3445-53. [DOI: 10.1016/j.febslet.2014.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 07/25/2014] [Accepted: 08/03/2014] [Indexed: 10/24/2022]
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Pandey D, Bhunia A, Oh YJ, Chang F, Bergman Y, Kim JH, Serbo J, Boronina TN, Cole RN, Van Eyk J, Remaley AT, Berkowitz DE, Romer LH. OxLDL triggers retrograde translocation of arginase2 in aortic endothelial cells via ROCK and mitochondrial processing peptidase. Circ Res 2014; 115:450-9. [PMID: 24903103 PMCID: PMC8760889 DOI: 10.1161/circresaha.115.304262] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Increased arginase activity contributes to endothelial dysfunction by competition for l-arginine substrate and reciprocal regulation of nitric oxide synthase (NOS). The rapid increase in arginase activity in human aortic endothelial cells exposed to oxidized low-density lipoprotein (OxLDL) is consistent with post-translational modification or subcellular trafficking. OBJECTIVE To test the hypotheses that OxLDL triggers reverse translocation of mitochondrial arginase 2 (Arg2) to cytosol and Arg2 activation, and that this process is dependent on mitochondrial processing peptidase, lectin-like OxLDL receptor-1 receptor, and rho kinase. METHODS AND RESULTS OxLDL-triggered translocation of Arg2 from mitochondria to cytosol in human aortic endothelial cells and in murine aortic intima with a concomitant rise in arginase activity. All of these changes were abolished by inhibition of mitochondrial processing peptidase or by its siRNA-mediated knockdown. Rho kinase inhibition and the absence of the lectin-like OxLDL receptor-1 in knockout mice also ablated translocation. Aminoterminal sequencing of Arg2 revealed 2 candidate mitochondrial targeting sequences, and deletion of either of these confined Arg2 to the cytoplasm. Inhibitors of mitochondrial processing peptidase or lectin-like OxLDL receptor-1 knockout attenuated OxLDL-mediated decrements in endothelial-specific NO production and increases in superoxide generation. Finally, Arg2(-/-) mice bred on an ApoE(-/-) background showed reduced plaque load, reduced reactive oxygen species production, enhanced NO, and improved endothelial function when compared with ApoE(-/-) controls. CONCLUSIONS These data demonstrate dual distribution of Arg2, a protein with an unambiguous mitochondrial targeting sequence, in mammalian cells, and its reverse translocation to cytoplasm by alterations in the extracellular milieu. This novel molecular mechanism drives OxLDL-mediated arginase activation, endothelial NOS uncoupling, endothelial dysfunction, and atherogenesis.
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Affiliation(s)
- Deepesh Pandey
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Anil Bhunia
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Young Jun Oh
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Fumin Chang
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Yehudit Bergman
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Jae Hyung Kim
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Janna Serbo
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Tatiana N Boronina
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Robert N Cole
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Jennifer Van Eyk
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Alan T Remaley
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Dan E Berkowitz
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Lewis H Romer
- From the Department of Anesthesiology and Critical Care Medicine (D.P., A.B., Y.J.O., F.C., Y.B., J.H.K., J.S., D.E.B., L.H.R.), Biomedical Engineering (J.S., D.E.B., L.H.R.), and Cell Biology, Pediatrics, Center for Cell Dynamics (L.H.R.), Mass Spectrometry and Proteomics Facility (T.N.B., R.N.C.), and Departments of Medicine and Biological Chemistry (J.V.E.), Johns Hopkins University School of Medicine, Baltimore, MD; and Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.).
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Xu G, Chen X, Liu L, Jiang L. Fumaric acid production in Saccharomyces cerevisiae by simultaneous use of oxidative and reductive routes. BIORESOURCE TECHNOLOGY 2013; 148:91-96. [PMID: 24045196 DOI: 10.1016/j.biortech.2013.08.115] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/16/2013] [Accepted: 08/19/2013] [Indexed: 05/28/2023]
Abstract
In this study, the simultaneous use of reductive and oxidative routes to produce fumaric acid was explored. The strain FMME003 (Saccharomyces cerevisiae CEN.PK2-1CΔTHI2) exhibited capability to accumulate pyruvate and was used for fumaric acid production. The fum1 mutant FMME004 could produce fumaric acid via oxidative route, but the introduction of reductive route derived from Rhizopus oryzae NRRL 1526 led to lower fumaric acid production. Analysis of the key factors associated with fumaric acid production revealed that pyruvate carboxylase had a low degree of control over the carbon flow to malic acid. The fumaric acid titer was improved dramatically when the heterologous gene RoPYC was overexpressed and 32 μg/L of biotin was added. Furthermore, under the optimal carbon/nitrogen ratio, the engineered strain FMME004-6 could produce up to 5.64 ± 0.16 g/L of fumaric acid. These results demonstrated that the proposed fermentative method is efficient for fumaric acid production.
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Affiliation(s)
- Guoqiang Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China; The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China
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Burak E, Yogev O, Sheffer S, Schueler-Furman O, Pines O. Evolving dual targeting of a prokaryotic protein in yeast. Mol Biol Evol 2013; 30:1563-73. [PMID: 23462316 DOI: 10.1093/molbev/mst039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dual targeting is an important and abundant phenomenon. Indeed, we estimate that more than a third of the yeast mitochondrial proteome is dual localized. The enzyme fumarase is a highly conserved protein in all organisms with respect to its sequence, structure, and enzymatic activity. In eukaryotes, it is dual localized to the cytosol and mitochondria. In Saccharomyces cerevisiae, the dual localization of fumarase is achieved by the reverse translocation mechanism; all fumarase molecules harbor a mitochondrial targeting sequence (MTS), are targeted to mitochondria, begin their translocation, and are processed by mitochondrial processing peptidase in the matrix. A subset of these processed fumarase molecules in transit is then fully imported into the matrix, whereas the majority moves back into the cytosol by reverse translocation. The proposed driving force for fumarase distribution is protein folding during import. Here, we asked how reverse translocation could have evolved on a prokaryotic protein that had already acquired expression from the nuclear genome and a targeting sequence. To address this question, we used, as a model, the Escherichia coli FumC Class II fumarase, which is homologous to eukaryotic fumarases (∼58% identity and ∼74% similarity to the yeast Fum1). Starting with an exclusively mitochondrial targeted FumC (attached to a strong MTS), we show that two randomly acquired mutations within the prokaryotic FumC sequence are sufficient to cause substantial dual targeting by reverse translocation. In fact, the unmutated MTS-FumC also has some ability to be dual targeted but only at low temperatures. Our results suggest that in this case, evolution of dual targeting by reverse translocation is based on naturally occurring and fortuitously conserved features of fumarase folding.
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Affiliation(s)
- Efrat Burak
- Department of Microbiology Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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Ishii H, Kunihiro S, Tanaka M, Hatano K, Nishikata T. Cytosolic subunits of ATP synthase are localized to the cortical endoplasmic reticulum-rich domain of the ascidian egg myoplasm. Dev Growth Differ 2013; 54:753-66. [PMID: 23067137 DOI: 10.1111/dgd.12003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Previously, we revealed that p58, one of the ascidian maternal factors, is identical to the alpha-subunit of F1-ATP synthase (ATPα), a protein complex of the inner mitochondrial membrane. In the current study, we used immunological probes for ascidian mitochondria components to show that the ascidian ATPα is ectopically localized to the cytosol. Virtually all mitochondrial components were localized to the mitochondria-rich myoplasm. However, in detail, ATP synthase subunits and the matrix proteins showed different localization patterns. At least at the crescent stage, transmission electron microscopy (TEM) distinguished the mitochondria-less, endoplasmic reticulum (ER)-rich cortical region and the mitochondria-rich internal region. ATPα was enriched in the cortical region and MnSOD was limited to the internal region. Using subcellular fractionation, although all of the mitochondria components were highly enriched in the mitochondria-enriched fraction, a considerable amount of ATPα and F1-ATP synthase beta-subunit (ATPβ) were recovered in the insoluble cytoplasmic fraction. Even under these conditions, F1-ATP synthase gamma-subunit (ATPγ) and F0-ATP synthase subunit b (ATPb) were not recovered in the insoluble cytoplasmic fraction. This result strongly supports the exomitochondrial localization of both ATPα and ATPβ. In addition, the detergent extraction of eggs supports the idea that these cytosolic ATP synthase subunits are associated with the egg cytoskeleton. These results suggest that the subunits of ATP synthase might play dual roles at different subcellular compartments during early development.
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Affiliation(s)
- Hirokazu Ishii
- Frontiers of Innovative Research in Science and Technology (FIRST), Konan University, Kobe, Hyogo, 650-0047, Japan.
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Otto C, Yovkova V, Aurich A, Mauersberger S, Barth G. Variation of the by-product spectrum during α-ketoglutaric acid production from raw glycerol by overexpression of fumarase and pyruvate carboxylase genes in Yarrowia lipolytica. Appl Microbiol Biotechnol 2012; 95:905-17. [PMID: 22539024 DOI: 10.1007/s00253-012-4085-1] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 04/03/2012] [Accepted: 04/04/2012] [Indexed: 11/29/2022]
Abstract
The yeast Yarrowia lipolytica secretes high amounts of various organic acids, like citric, isocitric, pyruvic (PA), and α-ketoglutaric (KGA) acids, triggered by growth limitation and excess of carbon source. This is leading to an increased interest in this non-conventional yeast for biotechnological applications. To improve the KGA production by Y. lipolytica for an industrial application, it is necessary to reduce the amounts of by-products, e.g., fumarate (FU) and PA, because production of by-products is a main disadvantage of the KGA production by this yeast. We have examined whether the concentration of secreted organic acids (main product KGA and PA as major by-product and FU, malate (MA), and succinate (SU) as minor by-products) can be influenced by a gene-dose-dependent overexpression of fumarase (FUM) or pyruvate carboxylase (PYC) genes under KGA production conditions. Recombinant Y. lipolytica strains were constructed, which harbor multiple copies of the respective FUM1, PYC1 or FUM1, and PYC1 genes. Overexpression of the genes FUM1 and PYC1 resulted in strongly increased specific enzyme activities during cultivation of these strains on raw glycerol as carbon source in bioreactors. The recombinant Y. lipolytica strains showed different product selectivity of the secreted organic acids KGA, PA, FU, MA, and SU. Concentrations of the by-products FU, MA, SU, and PA decreased significantly at overproduction of FUM and increased at overproduction of PYC and also of FUM and PYC simultaneously. In contrast, the production of KGA with the multicopy strains H355A(FUM1) and H355A(FUM1-PYC1) was comparable with the wild-type strain H355 or slightly lower in case of H355(PYC1). KGA productivity was not changed significantly compared with strain H355 whereas product selectivity of the main product KGA was increased in H355A(FUM1).
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Affiliation(s)
- Christina Otto
- Institut für Mikrobiologie, Technische Universität Dresden, Dresden, Germany.
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Xu G, Liu L, Chen J. Reconstruction of cytosolic fumaric acid biosynthetic pathways in Saccharomyces cerevisiae. Microb Cell Fact 2012; 11:24. [PMID: 22335940 PMCID: PMC3340314 DOI: 10.1186/1475-2859-11-24] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 02/15/2012] [Indexed: 11/12/2022] Open
Abstract
Background Fumaric acid is a commercially important component of foodstuffs, pharmaceuticals and industrial materials, yet the current methods of production are unsustainable and ecologically destructive. Results In this study, the fumarate biosynthetic pathway involving reductive reactions of the tricarboxylic acid cycle was exogenously introduced in S. cerevisiae by a series of simple genetic modifications. First, the Rhizopus oryzae genes for malate dehydrogenase (RoMDH) and fumarase (RoFUM1) were heterologously expressed. Then, expression of the endogenous pyruvate carboxylase (PYC2) was up-regulated. The resultant yeast strain, FMME-001 ↑PYC2 + ↑RoMDH, was capable of producing significantly higher yields of fumarate in the glucose medium (3.18 ± 0.15 g liter-1) than the control strain FMME-001 empty vector. Conclusions The results presented here provide a novel strategy for fumarate biosynthesis, which represents an important advancement in producing high yields of fumarate in a sustainable and ecologically-friendly manner.
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Affiliation(s)
- Guoqiang Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
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Abstract
The enzyme fumarase is a conserved protein in all organisms with regard to its sequence, structure and function. This enzyme participates in the tricarboxylic acid cycle in mitochondria which is essential for cellular respiration in eukaryotes. However, a common theme conserved from yeast to humans is the existence of a cytosolic form of fumarase; hence this protein is dual localized. We have coined identical (or nearly identical) proteins situated in different subcellular locations 'echoforms' or 'echoproteins'. Fumarase was the first example of a dual localized protein whose mechanism of distribution was found to be based on a single translation product. Consequently, fumarase has become a paradigm for three unique eukaryotic cellular phenomena related to protein dual localization: (a) distribution between mitochondria and the cytoplasm involves reverse translocation; (b) targeting to mitochondria involves translation coupled import; and (c) there are two echoforms possessing distinct functions in the respective subcellular compartments. Here we describe and discuss these fumarase related phenomena and in addition point out approaches for studying dual function of distributed proteins, in particular compartment-specific depletion. In the case of fumarase, the cytoplasmic function was only recently discovered; the enzyme was found to participate in the cellular response to DNA double strand breaks. Strikingly, upon DNA damage the protein is transported from the cytosol to the nucleus, where by virtue of its enzymatic activity it participates in the DNA damage response.
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Affiliation(s)
- Ohad Yogev
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
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Dimmer KS, Rapaport D. Unresolved mysteries in the biogenesis of mitochondrial membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1818:1085-90. [PMID: 21889926 DOI: 10.1016/j.bbamem.2011.08.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/10/2011] [Accepted: 08/15/2011] [Indexed: 10/17/2022]
Abstract
Mitochondria are essential eukaryotic organelles that are surrounded by two membranes. Both membranes contain a variety of different integral membrane proteins. After three decades of research on mitochondrial biogenesis five major import complexes with more than 40 subunits altogether were identified and characterized. In the current contribution we want to draw attention to some unexplored issues regarding the integration of mitochondrial membrane proteins and to formulate crucial questions that remain unanswered. This article is part of a Special Issue entitled: Protein Folding in Membranes.
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Affiliation(s)
- Kai Stefan Dimmer
- Interfaculty Institute of Biochemistry, University of Tübingen, 72076 Tübingen, Germany.
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Emerman AB, Zhang ZR, Chakrabarti O, Hegde RS. Compartment-restricted biotinylation reveals novel features of prion protein metabolism in vivo. Mol Biol Cell 2010; 21:4325-37. [PMID: 20980618 PMCID: PMC3002386 DOI: 10.1091/mbc.e10-09-0742] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Proteins are often made in more than one form, with alternate versions sometimes residing in different cellular compartments than the primary species. The mammalian prion protein (PrP), a cell surface GPI-anchored protein, is a particularly noteworthy example for which minor cytosolic and transmembrane forms have been implicated in disease pathogenesis. To study these minor species, we used a selective labeling strategy in which spatially restricted expression of a biotinylating enzyme was combined with asymmetric engineering of the cognate acceptor sequence into PrP. Using this method, we could show that even wild-type PrP generates small amounts of the (Ctm)PrP transmembrane form. Selective detection of (Ctm)PrP allowed us to reveal its N-terminal processing, long half-life, residence in both intracellular and cell surface locations, and eventual degradation in the lysosome. Surprisingly, some human disease-causing mutants in PrP selectively stabilized (Ctm)PrP, revealing a previously unanticipated mechanism of (Ctm)PrP up-regulation that may contribute to disease. Thus, spatiotemporal tagging has uncovered novel aspects of normal and mutant PrP metabolism and should be readily applicable to the analysis of minor topologic isoforms of other proteins.
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Affiliation(s)
- Amy B Emerman
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
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25
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O'Flaherty L, Adam J, Heather LC, Zhdanov AV, Chung YL, Miranda MX, Croft J, Olpin S, Clarke K, Pugh CW, Griffiths J, Papkovsky D, Ashrafian H, Ratcliffe PJ, Pollard PJ. Dysregulation of hypoxia pathways in fumarate hydratase-deficient cells is independent of defective mitochondrial metabolism. Hum Mol Genet 2010; 19:3844-51. [PMID: 20660115 PMCID: PMC2935862 DOI: 10.1093/hmg/ddq305] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 07/13/2010] [Indexed: 12/26/2022] Open
Abstract
Mutations in the gene encoding the Krebs cycle enzyme fumarate hydratase (FH) predispose to hereditary leiomyomatosis and renal cell cancer in affected individuals. FH-associated neoplasia is characterized by defective mitochondrial function and by upregulation of transcriptional pathways mediated by hypoxia-inducible factor (HIF), although whether and by what means these processes are linked has been disputed. We analysed the HIF pathway in Fh1-/- mouse embryonic fibroblasts (MEFs), in FH-defective neoplastic tissues and in Fh1-/- MEFs re-expressing either wild-type or an extra-mitochondrial restricted form of FH. These experiments demonstrated that upregulation of HIF-1alpha occurs as a direct consequence of FH inactivation. Fh1-/- cells accumulated intracellular fumarate and manifested severe impairment of HIF prolyl but not asparaginyl hydroxylation which was corrected by provision of exogenous 2-oxoglutarate (2-OG). Re-expression of the extra-mitochondrial form of FH in Fh1-/- cells was sufficient to reduce intracellular fumarate and to correct dysregulation of the HIF pathway completely, even in cells that remained profoundly defective in mitochondrial energy metabolism. The findings indicate that upregulation of HIF-1alpha arises from competitive inhibition of the 2-OG-dependent HIF hydroxylases by fumarate and not from disruption of mitochondrial energy metabolism.
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Affiliation(s)
- Linda O'Flaherty
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Julie Adam
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Lisa C. Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3QX, UK
| | - Alexander V. Zhdanov
- Department of Biochemistry, University College Cork, Cavanagh Pharmacy Building, 1.28 College Road, Cork, Ireland
| | - Yuen-Li Chung
- CRUK and ESPRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Hospital, Sutton, Surrey SM2 5PT, UK
| | - Melroy X. Miranda
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Joanne Croft
- The Sheffield Children's NHS Trust, Immuno Bank, Sheffield S10 2TH, UK
| | - Simon Olpin
- The Sheffield Children's NHS Trust, Immuno Bank, Sheffield S10 2TH, UK
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3QX, UK
| | - Christopher W. Pugh
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - John Griffiths
- Cancer Research UK Cambridge Research Institute, Li Ka Shing Centre, Robinson Way, Cambridge CB2 0RE, UK and
| | - Dmitri Papkovsky
- Department of Biochemistry, University College Cork, Cavanagh Pharmacy Building, 1.28 College Road, Cork, Ireland
| | - Houman Ashrafian
- Department of Cardiovascular Medicine, University of Oxford, Level 6, West Wing, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DU, UK
| | - Peter J. Ratcliffe
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Patrick J. Pollard
- Henry Wellcome Building for Molecular Physiology, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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26
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Yogev O, Yogev O, Singer E, Shaulian E, Goldberg M, Fox TD, Pines O. Fumarase: a mitochondrial metabolic enzyme and a cytosolic/nuclear component of the DNA damage response. PLoS Biol 2010; 8:e1000328. [PMID: 20231875 PMCID: PMC2834712 DOI: 10.1371/journal.pbio.1000328] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Accepted: 02/03/2010] [Indexed: 02/07/2023] Open
Abstract
Upon DNA damage, a cytosolic form of the mitochondrial enzyme fumarase moves into the nucleus where, by virtue of its enzymatic activity, it participates in the cell's response to DNA damage. This potentially explains its known role as a tumor suppressor. In eukaryotes, fumarase (FH in human) is a well-known tricarboxylic-acid-cycle enzyme in the mitochondrial matrix. However, conserved from yeast to humans is a cytosolic isoenzyme of fumarase whose function in this compartment remains obscure. A few years ago, FH was surprisingly shown to underlie a tumor susceptibility syndrome, Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC). A biallelic inactivation of FH has been detected in almost all HLRCC tumors, and therefore FH was suggested to function as a tumor suppressor. Recently it was suggested that FH inhibition leads to elevated intracellular fumarate, which in turn acts as a competitive inhibitor of HPH (HIF prolyl hydroxylase), thereby causing stabilization of HIF (Hypoxia-inducible factor) by preventing proteasomal degradation. The transcription factor HIF increases the expression of angiogenesis regulated genes, such as VEGF, which can lead to high microvessel density and tumorigenesis. Yet this mechanism does not fully explain the large cytosolic population of fumarase molecules. We constructed a yeast strain in which fumarase is localized exclusively to mitochondria. This led to the discovery that the yeast cytosolic fumarase plays a key role in the protection of cells from DNA damage, particularly from DNA double-strand breaks. We show that the cytosolic fumarase is a member of the DNA damage response that is recruited from the cytosol to the nucleus upon DNA damage induction. This function of fumarase depends on its enzymatic activity, and its absence in cells can be complemented by high concentrations of fumaric acid. Our findings suggest that fumarase and fumaric acid are critical elements of the DNA damage response, which underlies the tumor suppressor role of fumarase in human cells and which is most probably HIF independent. This study shows an exciting crosstalk between primary metabolism and the DNA damage response, thereby providing a scenario for metabolic control of tumor propagation. Fumarate hydratase (FH; also known as fumarase) is an enzyme found in both the cytoplasm and mitochondria of all eukaryotes. In mitochondria, FH is involved in generating energy for the cell through a metabolic pathway called the Krebs cycle. Its role in the cytoplasm, however, is unclear. FH can function as a tumor suppressor: its absence is linked to the formation of human kidney tumors in a syndrome termed HLRCC. We show here that the cytoplasmic version of FH has an unexpected role in repairing DNA double-strand breaks in the nucleus. This role involves the movement of FH from the cytoplasm into the nucleus and depends on its enzymatic activity. Strikingly, when FH is absent from cells, its function in DNA repair can be substituted by high concentrations of one of the enzyme's products, fumaric acid. Our findings imply that FH deficiency leads to cancer because there is not enough fumaric acid in the nucleus to stimulate repair of DNA double-strand breaks; the persistence of these breaks is believed to provoke cancer. The study thus makes a surprising connection between primary metabolism and the cell's response to DNA damage.
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Affiliation(s)
- Ohad Yogev
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Orli Yogev
- Department of Biochemistry and Molecular Biology, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Esti Singer
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Eitan Shaulian
- Department of Biochemistry and Molecular Biology, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
| | - Michal Goldberg
- Department of Genetics, The Institute of Life Sciences, The Hebrew University, Jerusalem, Israel
| | - Thomas D. Fox
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Ophry Pines
- Department of Microbiology and Molecular Genetics, IMRIC, Faculty of Medicine, Hebrew University, Jerusalem, Israel
- * E-mail:
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27
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Herrmann JM. Putting a break on protein translocation: metabolic regulation of mitochondrial protein import. Mol Microbiol 2009; 72:275-8. [PMID: 19415790 DOI: 10.1111/j.1365-2958.2009.06660.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sequence-inherent targeting information directs polypeptides synthesized in the cytosol to their respective cellular compartment. Some proteins use ambiguous sorting signals or specific folding properties to be dually distributed between the cytosol and mitochondria. A study published in this issue of Molecular Microbiology shows that in the case of fumarase this distribution is controlled by the metabolic state of yeast cells. The metabolite-dependent distribution of fumarase represents an exciting example of regulated protein import into mitochondria that shows that eukaryotes can adapt the intracellular protein distribution to their physiological conditions.
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28
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Ahmed AU, Fisher PR. Import of nuclear-encoded mitochondrial proteins: a cotranslational perspective. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 273:49-68. [PMID: 19215902 DOI: 10.1016/s1937-6448(08)01802-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A growing amount of evidence suggests that the cytosolic translation of nuclear-encoded mitochondrial proteins and their subsequent import into mitochondria are tightly coupled in a process termed cotranslational import. In addition to the original posttranslational view of mitochondrial protein import, early literature also provides both in vitro and in vivo experimental evidence supporting the simultaneous existence of a cotranslational protein-import mechanism in mitochondria. Recent investigations have started to reveal the cotranslational import mechanism which is initiated by transporting either a translation complex or a translationally competent mRNA encoding a mitochondrial protein to the mitochondrial surface. The intracellular localization of mRNA to the mitochondrial surface has emerged as the latest addition to our understanding of mitochondrial biogenesis. It is mediated by targeting elements within the mRNA molecule in association with potential mRNA-binding proteins.
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Affiliation(s)
- Afsar U Ahmed
- Department of Microbiology, La Trobe University, Victoria, Australia
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29
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Mutations in LPIN1 cause recurrent acute myoglobinuria in childhood. Am J Hum Genet 2008; 83:489-94. [PMID: 18817903 DOI: 10.1016/j.ajhg.2008.09.002] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2008] [Revised: 08/30/2008] [Accepted: 09/05/2008] [Indexed: 12/16/2022] Open
Abstract
Recurrent episodes of life-threatening myoglobinuria in childhood are caused by inborn errors of glycogenolysis, mitochondrial fatty acid beta-oxidation, and oxidative phosphorylation. Nonetheless, approximately half of the patients do not suffer from a defect in any of these pathways. Using homozygosity mapping, we identified six deleterious mutations in the LPIN1 gene in patients who presented at 2-7 years of age with recurrent, massive rhabdomyolysis. The LPIN1 gene encodes the muscle-specific phosphatidic acid phosphatase, a key enzyme in triglyceride and membrane phospholipid biosynthesis. Of six individuals who developed statin-induced myopathy, one was a carrier for Glu769Gly, a pathogenic mutation in the LPIN1 gene. Analysis of phospholipid content disclosed accumulation of phosphatidic acid and lysophospholipids in muscle tissue of the more severe genotype. Mutations in the LPIN1 gene cause recurrent rhabdomyolysis in childhood, and a carrier state may predispose for statin-induced myopathy.
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30
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Regev-Rudzki N, Yogev O, Pines O. The mitochondrial targeting sequence tilts the balance between mitochondrial and cytosolic dual localization. J Cell Sci 2008; 121:2423-31. [DOI: 10.1242/jcs.029207] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dual localization of proteins in the cell has appeared in recent years to be a more abundant phenomenon than previously reported. One of the mechanisms by which a single translation product is distributed between two compartments, involves retrograde movement of a subset of processed molecules back through the organelle-membrane. Here, we investigated the specific contribution of the mitochondrial targeting sequence (MTS), as a cis element, in the distribution of two proteins, aconitase and fumarase. Whereas the cytosolic presence of fumarase is obvious, the cytosolic amount of aconitase is minute. Therefore, we created (1) MTS-exchange mutants, exchanging the MTS of aconitase and fumarase with each other as well as with those of other proteins and, (2) a set of single mutations, limited to the MTS of these proteins. Distribution of both proteins is affected by mutations, a fact particularly evident for aconitase, which displays extraordinary amounts of processed protein in the cytosol. Thus, we show for the first time, that the MTS has an additional role beyond targeting: it determines the level of retrograde movement of proteins back into the cytosol. Our results suggest that the translocation rate and folding of proteins during import into mitochondria determines the extent to which molecules are withdrawn back into the cytosol.
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Affiliation(s)
- Neta Regev-Rudzki
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
| | - Ohad Yogev
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
| | - Ophry Pines
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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31
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Raimundo N, Ahtinen J, Fumić K, Barić I, Remes AM, Renkonen R, Lapatto R, Suomalainen A. Differential metabolic consequences of fumarate hydratase and respiratory chain defects. Biochim Biophys Acta Mol Basis Dis 2008; 1782:287-94. [DOI: 10.1016/j.bbadis.2008.01.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Accepted: 01/22/2008] [Indexed: 12/28/2022]
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32
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Yogev O, Karniely S, Pines O. Translation-coupled Translocation of Yeast Fumarase into Mitochondria in Vivo. J Biol Chem 2007; 282:29222-9. [PMID: 17666392 DOI: 10.1074/jbc.m704201200] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fumarase represents proteins that cannot be imported into mitochondria after the termination of translation (post-translationally). Utilizing mitochondrial and cytosolic versions of the tobacco etch virus (TEV) protease, we show that mitochondrially targeted fumarase harboring a TEV protease recognition sequence is efficiently cleaved by the mitochondrial but not by the cytosolic TEV protease. Nonetheless, fumarase was readily cleaved by cytosolic TEV when its import into mitochondria was slowed down by either (i) disrupting the activity of the TOM complex, (ii) lowering the growth temperature, or (iii) reducing the inner membrane electrochemical potential. Accessibility of the fumarase nascent chain to TEV protease under such conditions was prevented by low cycloheximide concentrations, which impede translation. In addition, depletion of the ribosome-associated nascent polypeptide-associated complex (NAC) reduced the fumarase rate of translocation into mitochondria and exposed it to TEV cleavage in the cytosol. These results indicate that cytosolic exposure of the fumarase nascent chain depends on both translocation and translation rates, allowing us to discuss the possibility that import of fumarase into mitochondria occurs while the ribosome is still attached to the nascent chain.
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Affiliation(s)
- Ohad Yogev
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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33
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Reisch AS, Elpeleg O. Biochemical assays for mitochondrial activity: assays of TCA cycle enzymes and PDHc. Methods Cell Biol 2007; 80:199-222. [PMID: 17445696 DOI: 10.1016/s0091-679x(06)80010-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Ann Saada Reisch
- The Metabolic Disease Unit, Hadassah-Hebrew University Medical Centre, Jerusalem 91120, Israel
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34
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Regev-Rudzki N, Pines O. Eclipsed distribution: A phenomenon of dual targeting of protein and its significance. Bioessays 2007; 29:772-82. [PMID: 17621655 DOI: 10.1002/bies.20609] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
One of the surprises from genome sequencing projects is the apparently small number of predicted genes in different eukaryotic cells, particularly human. One possible reason for this 'shortage' of genes is multiple distribution of proteins; a single protein is targeted to more than one subcellular compartment and consequently participates in different biochemical pathways and might have completely different functions. Indeed, in recent years, there have been reports on proteins that were found to be localized in cellular compartments other than those initially attributed to them. Furthermore, the phenomenon of highly uneven isoprotein distribution was recently observed and termed 'eclipsed distribution'. In these cases, the amount of one of the isoproteins, in one of the locations, is significantly minute and its detection by standard biochemical and visualization methods is masked by the presence of the dominant isoprotein. In fact, the minute amounts of eclipsed proteins can be essential. Since detecting eclipsed distribution is difficult, we assume that this phenomenon is probably more common than currently recorded. Hence, developing methods for localization and functional detection of eclipsed proteins is a challenge in cell biology research. Finally, eclipsed distribution may lead to cellular pathologies as has been suggested to occur in human disorders such as Prion diseases and Alzheimer. This review provides a short description of the eclipsed distribution phenomenon followed by an overview of protein distribution mechanisms, examples of eclipsed distribution and experimental approaches for revealing these elusive proteins.
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Affiliation(s)
- Neta Regev-Rudzki
- Molecular Biology, Medical School, Hebrew University of Jerusalem, Jerusalem, Israel
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35
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Brière JJ, Favier J, Gimenez-Roqueplo AP, Rustin P. Tricarboxylic acid cycle dysfunction as a cause of human diseases and tumor formation. Am J Physiol Cell Physiol 2006; 291:C1114-20. [PMID: 16760265 DOI: 10.1152/ajpcell.00216.2006] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A renewed interest in tricarboxylic acid cycle enzymopathies has resulted from the report that, in addition to devastating encephalopathies, these can result in various types of tumors in human. We first review the major features of the cycle that may underlie this surprising variety of clinical features. After discussing the rare cases of encephalopathies associated with specific deficiencies of some of the tricarboxylic acid cycle enzyme, we finally examine the mechanism possibly causing tumor/cancer formation in the cases of mutations affecting fumarase or succinate dehydrogenase genes.
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Affiliation(s)
- Jean-Jacques Brière
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 676, Hôpital Robert Debré, Paris
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36
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Bowes T, Singh B, Gupta RS. Subcellular localization of fumarase in mammalian cells and tissues. Histochem Cell Biol 2006; 127:335-46. [PMID: 17111171 DOI: 10.1007/s00418-006-0249-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/2006] [Indexed: 11/29/2022]
Abstract
Fumarase, a mitochondrial matrix protein, is previously indicated to be present in substantial amounts in the cytosol as well. However, recent studies show that newly synthesized human fumarase is efficiently imported into mitochondria with no detectable amount in the cytosol. To clarify its subcellular localization, the subcellular distribution of fumarase in mammalian cells/tissues was examined by a number of different methods. Cell fractionation using either a mitochondria fraction kit or extraction with low concentrations of digitonin, detected no fumarase in a 100,000 g supernatant fraction. Immunofluorescence labeling with an affinity-purified antibody to fumarase and an antibody to the mitochondrial Hsp60 protein showed identical labeling pattern with labeling seen mainly in mitochondria. Detailed studies were performed using high-resolution immunogold electron microscopy to determine the subcellular localization of fumarase in rat tissues, embedded in LR White resin. In thin sections from kidney, liver, heart, adrenal gland and anterior pituitary, strong and specific labeling due to fumarase antibody was only detected in mitochondria. However, in the pancreatic acinar cells, in addition to mitochondria, highly significant labeling was also observed in the zymogen granules and endoplasmic reticulum. The observed labeling in all cases was completely abolished upon omission of the primary antibody indicating that it was specific. In a western blot of purified zymogen granules, a fumarase-antibody cross-reactive protein of the same molecular mass as seen in the mitochondria was present. These results provide evidence that fumarase in mammalian cells/tissues is mainly localized in mitochondria and significant amounts of this protein are not present in the cytosol. However, these studies also reveal that in certain tissues, in addition to mitochondria, this protein is also present at specific extramitochondrial sites. Although the cellular function of fumarase at these extramitochondrial locations is not known, the appearance/localization of fumarase outside mitochondria may help explain how mutations in this mitochondrial protein can give rise to a number of different types of cancers.
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Affiliation(s)
- Timothy Bowes
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada, L8N 3Z5
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37
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Karniely S, Rayzner A, Sass E, Pines O. Alpha-complementation as a probe for dual localization of mitochondrial proteins. Exp Cell Res 2006; 312:3835-46. [PMID: 17034789 DOI: 10.1016/j.yexcr.2006.08.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 08/12/2006] [Accepted: 08/15/2006] [Indexed: 11/23/2022]
Abstract
There are a growing number of proteins which are reported to reside in multiple compartments within the eukaryotic cell. However, lack of appropriate methods limits our knowledge on the true extent of this phenomenon. In this study, we demonstrate a novel application of beta-galactosidase alpha-complementation to study dual distribution of proteins in yeast cells. Using a simple colony color phenotype, we show that alpha-complementation depends on co-compartmentalization of alpha and omega fragments and exploit this to probe dual localization of proteins between the cytosol and mitochondria in yeast. The quality of our assay was assessed by analysis of the known dual targeted enzyme fumarase and several mutant derivatives, which are exclusively localized to one or the other of these subcellular compartments. Addition of the alpha fragment did not abolish the enzymatic activity of the tagged proteins nor did it affect their localization. By examining 10 yeast gene products for distribution between the cytosol and the mitochondria, we demonstrate the potential of alpha-complementation to screen the mitochondrial proteome for dual distribution. Our data indicate the distribution of two uncharacterized proteins--Bna3 and Nif3--between the cytosol and the mitochondria.
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Affiliation(s)
- Sharon Karniely
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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38
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Huang HY, Kuei Y, Chao HY, Chen SJ, Yeh LS, Wang CC. Cross-species and Cross-compartmental Aminoacylation of Isoaccepting tRNAs by a Class II tRNA Synthetase. J Biol Chem 2006; 281:31430-9. [PMID: 16928688 DOI: 10.1074/jbc.m601869200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
It was previously shown that ALA1, the only alanyl-tRNA synthetase gene in Saccharomyces cerevisiae, codes for two functionally exclusive protein isoforms through alternative initiation at two consecutive ACG codons and an in-frame downstream AUG. We reported here the cloning and characterization of a homologous gene from Candida albicans. Functional assays show that this gene can substitute for both the cytoplasmic and mitochondrial functions of ALA1 in S. cerevisiae and codes for two distinct protein isoforms through alternative initiation from two in-frame AUG triplets 8-codons apart. Unexpectedly, although the short form acts exclusively in cytoplasm, the longer form provides function in both compartments. Similar observations are made in fractionation assays. Thus, the alanyl-tRNA synthetase gene of C. albicans has evolved an unusual pattern of translation initiation and protein partitioning and codes for protein isoforms that can aminoacylate isoaccepting tRNAs from a different species and from across cellular compartments.
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Affiliation(s)
- Hsiao-Yun Huang
- Department of Life Science, National Central University, Jung-li, Taiwan 32001
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39
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Singh B, Gupta RS. Mitochondrial import of human and yeast fumarase in live mammalian cells: Retrograde translocation of the yeast enzyme is mainly caused by its poor targeting sequence. Biochem Biophys Res Commun 2006; 346:911-8. [PMID: 16774737 DOI: 10.1016/j.bbrc.2006.05.188] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 05/31/2006] [Indexed: 10/24/2022]
Abstract
Studies on yeast fumarase provide the main evidence for dual localization of a protein in mitochondria and cytosol by means of retrograde translocation. We have examined the subcellular targeting of yeast and human fumarase in live cells to identify factors responsible for this. The cDNAs for mature yeast or human fumarase were fused to the gene for enhanced green fluorescent protein (eGFP) and they contained, at their N-terminus, a mitochondrial targeting sequence (MTS) derived from either yeast fumarase, human fumarase, or cytochrome c oxidase subunit VIII (COX) protein. Two nuclear localization sequences (2x NLS) were also added to these constructs to facilitate detection of any cytosolic protein by its targeting to nucleus. In Cos-1 cells transfected with these constructs, human fumarase with either the native or COX MTSs was detected exclusively in mitochondria in >98% of the cells, while the remainder 1-2% of the cells showed varying amounts of nuclear labeling. In contrast, when human fumarase was fused to the yeast MTS, >50% of the cells showed nuclear labeling. Similar studies with yeast fumarase showed that with its native MTS, nuclear labeling was seen in 80-85% of the cells, but upon fusion to either human or COX MTS, nuclear labeling was observed in only 10-15% of the cells. These results provide evidence that extramitochondrial presence of yeast fumarase is mainly caused by the poor mitochondrial targeting characteristics of its MTS (but also affected by its primary sequence), and that the retrograde translocation mechanism does not play a significant role in the extramitochondrial presence of mammalian fumarase.
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Affiliation(s)
- Bhag Singh
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada L8N 3Z5
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40
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Karniely S, Regev-Rudzki N, Pines O. The presequence of fumarase is exposed to the cytosol during import into mitochondria. J Mol Biol 2006; 358:396-405. [PMID: 16530220 DOI: 10.1016/j.jmb.2006.02.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2006] [Revised: 02/07/2006] [Accepted: 02/09/2006] [Indexed: 11/28/2022]
Abstract
The majority of mitochondrial proteins can be imported into mitochondria following termination of their translation in the cytosol. Import of fumarase and several other proteins into mitochondria does not appear to occur post-translationally according to standard in vivo and in vitro assays. However, the nature of interaction between the translation and translocation apparatuses during import of these proteins is unknown. Therefore, a major question is whether the nascent chains of these proteins are exposed to the cytosol during import into mitochondria. We asked directly if the presequence of fumarase can be cleaved by externally added mitochondrial processing peptidase (MPP) during import, using an in vitro translation-translocation coupled reaction. The presequence of fumarase was cleaved by externally added MPP during import, indicating a lack of, or a loose physical connection between, the translation and translocation of this protein. Exchanging the authentic presequence of fumarase for that of the more efficient Su9-ATPase presequence reduced the exposure of fumarase precursors to externally added MPP en route to mitochondria. Therefore, exposure to cytosolic MPP is dependent on the presequence and not on the mature part of fumarase. On the other hand, following translation in the absence of mitochondria, the authentic fumarase presequence and that of Su9-ATPase become inaccessible to added MPP when attached to mature fumarase. Thus, folding of the mature portion of fumarase, which conceals the presequence, is the reason for its inability to be imported in classical post-translational assays. Another unique feature of fumarase is its distribution between the mitochondria and the cytosol. We show that in vivo the switch of the authentic presequence with that of Su9-ATPase caused more fumarase molecules to be localized to the mitochondria. A possible mechanism by which the cytosolic exposure, the targeting efficiency, and the subcellular distribution of fumarase are dictated by the presequence is discussed.
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Affiliation(s)
- Sharon Karniely
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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41
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Sadacharan SK, Singh B, Bowes T, Gupta RS. Localization of mitochondrial DNA encoded cytochrome c oxidase subunits I and II in rat pancreatic zymogen granules and pituitary growth hormone granules. Histochem Cell Biol 2005; 124:409-21. [PMID: 16133117 DOI: 10.1007/s00418-005-0056-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2005] [Indexed: 10/25/2022]
Abstract
Cytochrome c oxidase (COX) complex is an integral part of the electron transport chain. Three subunits of this complex (COX I, COX II and COX III) are encoded by mitochondrial (mit-) DNA. High-resolution immunogold electron microscopy has been used to study the subcellular localization of COX I and COX II in rat tissue sections, embedded in LR Gold resin, using monoclonal antibodies for these proteins. Immunofluorescence labeling of BS-C-1 monkey kidney cells with these antibodies showed characteristic mitochondrial labeling. In immunogold labeling studies, the COX I and COX II antibodies showed strong and specific mitochondrial labeling in the liver, kidney, heart and pancreas. However, in rat pancreatic acinar tissue, in addition to mitochondrial labeling, strong and specific labeling was also observed in the zymogen granules (ZGs). In the anterior pituitary, strong labeling with these antibodies was seen in the growth hormone secretory granules. In contrast to these compartments, the COX I or COX II antibodies showed only minimal labeling (five- to tenfold lower) of the cytoplasm, endoplasmic reticulum and the nucleus. Strong labeling with the COX I or COX II antibodies was also observed in highly purified ZGs from bovine pancreas. The observed labeling, in all cases, was completely abolished upon omission of the primary antibodies. These results provide evidence that, similar to a number of other recently studied mit-proteins, COX I and COX II are also present outside the mitochondria. The presence of mit-DNA encoded COX I and COX II in extramitochondrial compartments, provides strong evidence that proteins can exit, or are exported, from the mitochondria. Although the mechanisms responsible for protein exit/export remain to be elucidated, these results raise fundamental questions concerning the roles of mitochondria and mitochondrial proteins in diverse cellular processes in different compartments.
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Affiliation(s)
- Skanda K Sadacharan
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Canada, L8N 3Z5
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42
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Karniely S, Pines O. Single translation--dual destination: mechanisms of dual protein targeting in eukaryotes. EMBO Rep 2005; 6:420-5. [PMID: 15864293 PMCID: PMC1299304 DOI: 10.1038/sj.embor.7400394] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Accepted: 02/23/2005] [Indexed: 11/09/2022] Open
Abstract
It is well documented that single eukaryotic genes can give rise to proteins that are localized to several subcellular locations. This is achieved at the level of transcription, splicing and translation, and results in two or more translation products that either harbour or lack specific targeting signals. Nevertheless, the possibility of dual targeting of a single translation product has recently emerged. Here, we review cases of such dual targeting with emphasis on the mechanisms through which these phenomena occur. Proteins that harbour one signal, two separate signals or an overlapping ambiguous signal may follow dual distribution in the cell. The mechanism of dual targeting is driven by the competition or promiscuity of various molecular events. Protein folding, post-translational modification and protein-protein interaction are key players in this phenomenon.
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Affiliation(s)
- Sharon Karniely
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
| | - Ophry Pines
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
- Tel: +972 2 675 7203; Fax: +972 2 675 7260;
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Regev-Rudzki N, Karniely S, Ben-Haim NN, Pines O. Yeast aconitase in two locations and two metabolic pathways: seeing small amounts is believing. Mol Biol Cell 2005; 16:4163-71. [PMID: 15975908 PMCID: PMC1196327 DOI: 10.1091/mbc.e04-11-1028] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The distribution of identical enzymatic activities between different subcellular compartments is a fundamental process of living cells. At present, the Saccharomyces cerevisiae aconitase enzyme has been detected only in mitochondria, where it functions in the tricarboxylic acid (TCA) cycle and is considered a mitochondrial matrix marker. We developed two strategies for physical and functional detection of aconitase in the yeast cytosol: 1) we fused the alpha peptide of the beta-galactosidase enzyme to aconitase and observed alpha complementation in the cytosol; and 2) we created an ACO1-URA3 hybrid gene, which allowed isolation of strains in which the hybrid protein is exclusively targeted to mitochondria. These strains display a specific phenotype consistent with glyoxylate shunt elimination. Together, our data indicate that yeast aconitase isoenzymes distribute between two distinct subcellular compartments and participate in two separate metabolic pathways; the glyoxylate shunt in the cytosol and the TCA cycle in mitochondria. We maintain that such dual distribution phenomena have a wider occurrence than recorded currently, the reason being that in certain cases there is a small fraction of one of the isoenzymes, in one of the locations, making its detection very difficult. We term this phenomenon of highly uneven isoenzyme distribution "eclipsed distribution."
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Affiliation(s)
- Neta Regev-Rudzki
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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Mühlenhoff U, Balk J, Richhardt N, Kaiser JT, Sipos K, Kispal G, Lill R. Functional Characterization of the Eukaryotic Cysteine Desulfurase Nfs1p from Saccharomyces cerevisiae. J Biol Chem 2004; 279:36906-15. [PMID: 15220327 DOI: 10.1074/jbc.m406516200] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies have indicated that the essential protein Nfs1 performs a crucial role in cellular iron-sulfur (Fe/S) protein maturation. The protein is located predominantly in mitochondria, yet low amounts are present in cytosol and nucleus. Here we examined several aspects concerning the molecular function of yeast Nfs1p as a model protein. First, we demonstrated that purified Nfs1p facilitates the in vitro assembly of Fe/S proteins by using cysteine as its specific substrate. Thus, eukaryotic Nfs1 is a functional orthologue of the bacterial cysteine desulfurase IscS. Second, we showed that only the mitochondrial version but not the extramitochondrial version of Nfs1p is functional in generating cytosolic and nuclear Fe/S proteins. Mutation of the nuclear targeting signal of Nfs1p did not affect the maturation of cytosolic and nuclear Fe/S proteins, despite a severe growth defect under this condition. Nfs1p could not assemble an Fe/S cluster on the Isu scaffold proteins when they were located in the yeast cytosol. The lack of function of these central Fe/S cluster assembly components suggests that the maturation of extramitochondrial Fe/S protein does not involve functional copies of the mitochondrial Fe/S cluster assembly machinery in the yeast cytosol. Third, the extramitochondrial version of Nfs1p was shown to play a direct role in the thiomodification of tRNAs. Finally, we identified a highly conserved N-terminal beta-sheet of Nfs1p as a functionally essential part of the protein. The implication of these findings for the structural stability of Nfs1p and for its targeting mechanism to mitochondria and cytosol/nucleus will be discussed.
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Affiliation(s)
- Ulrich Mühlenhoff
- Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch Strasse 6, 35033 Marburg, Germany
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Danpure CJ. How can the products of a single gene be localized to more than one intracellular compartment? Trends Cell Biol 2004; 5:230-8. [PMID: 14732127 DOI: 10.1016/s0962-8924(00)89016-9] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Protein-targeting sequences are specific for each intracellular compartment, so that most proteins are found at only one location within the eukaryotic cell. Increasingly, however, examples are being found of proteins that occur and function in more than one cellular compartment. In some cases, the multicompartmentalized isoforms are encoded by the same gene. Several mechanisms have evolved to enable such genes to encode and differentially express multiple types of topogenic information. These mechanisms include alternative forms of transcription initiation, translation initiation, splicing and post-translational modification.
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Affiliation(s)
- C J Danpure
- MRC Protein Translocation Group at the Dept of Biology, University College London, Gower Street, London, WC1E 6BT, UK
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Chang KJ, Wang CC. Translation initiation from a naturally occurring non-AUG codon in Saccharomyces cerevisiae. J Biol Chem 2004; 279:13778-85. [PMID: 14734560 DOI: 10.1074/jbc.m311269200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Although previous studies have already shown that both cytoplasmic and mitochondrial activities of glycyl-tRNA synthetase are provided by a single gene, GRS1,in the yeast Saccharomyces cerevisiae, the mechanism by which this occurs remains unclear. Evidence presented here indicates that this bifunctional property is actually a result of two distinct translational products alternatively generated from a single transcript of this gene. Except for an amino-terminal 23-amino acid extension, these two isoforms have the same polypeptide sequence and function exclusively in their respective compartments under normal conditions. Reporter gene assays further suggest that this leader peptide can function independently as a mitochondrial targeting signal and plays the major role in the subcellular localization of the isoforms. Additionally, whereas the short protein is translationally initiated from a traditional AUG triplet, the longer isoform is generated from an upstream inframe UUG codon. To our knowledge, GRS1 appears to be the first example in the yeast wherein a functional protein isoform is initiated from a naturally occurring non-AUG codon. The results suggest that non-AUG initiation might be a mechanism existing throughout all kingdoms.
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Affiliation(s)
- Kuang-Jung Chang
- Department of Life Science, National Central University, 300 Jung-da, Jung-li, Taiwan 32054
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Outten CE, Culotta VC. Alternative start sites in the Saccharomyces cerevisiae GLR1 gene are responsible for mitochondrial and cytosolic isoforms of glutathione reductase. J Biol Chem 2003; 279:7785-91. [PMID: 14672937 PMCID: PMC3829004 DOI: 10.1074/jbc.m312421200] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To combat oxidative damage, eukaryotic cells have evolved with numerous anti-oxidant factors that are often distributed between cytosolic and mitochondrial pools. Glutathione reductase, which regenerates the reduced form of glutathione, represents one such anti-oxidant factor, yet nothing is known regarding the partitioning of this enzyme within the cell. Using the bakers' yeast Saccharomyces cerevisiae as a model, we provide evidence that a single gene, namely GLR1, encodes both the mitochondrial and cytosolic forms of glutathione reductase. A deletion in GLR1 drastically increases levels of oxidized glutathione in these two subcellular compartments. The GLR1 gene has two inframe start codons that are both used as translation initiation sites. Translation from the first codon generates the mitochondrial form that includes a mitochondrial targeting signal, whereas translation from the second codon produces the cytosolic form that lacks this sequence. Our results indicate that the sequence context of the two AUG codons influences the efficiency of translation initiation at each site, which in turn affects the relative levels of cytosolic and mitochondrial Glr1p. This method of subcellular distribution of glutathione reductase may be conserved in mammalian cells as well.
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Affiliation(s)
| | - Valeria C. Culotta
- To whom correspondence should be addressed: , Telephone: 410-955-3029, Fax: 410-955-0116
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Sass E, Karniely S, Pines O. Folding of fumarase during mitochondrial import determines its dual targeting in yeast. J Biol Chem 2003; 278:45109-16. [PMID: 12960177 DOI: 10.1074/jbc.m302344200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously proposed that a single translation product of the FUM1 gene encoding fumarase is distributed between the cytosol and mitochondria of Saccharomyces cerevisiae and that all fumarase translation products are targeted and processed in mitochondria before distribution. Thus, fumarase processed in mitochondria returns to the cytosol. In the current work, we (i) generated mutations throughout the coding sequence which resulted in fumarases with altered conformations that are targeted to mitochondria but have lost their ability to be distributed; (ii) showed by mass spectrometry that mature cytosolic and mitochondrial fumarase isoenzymes are identical; and (iii) showed that hsp70 chaperones in the cytosol (Ssa) and mitochondria (Ssc1) can affect fumarase distribution. The results are discussed in light of our model of targeting and distribution, which suggests that rapid folding of fumarase into an import-incompetent state provides the driving force for retrograde movement of the processed protein back to the cytosol through the translocation pore.
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Affiliation(s)
- Ehud Sass
- Department of Molecular Biology, Hebrew University Medical School, Jerusalem 91120, Israel
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Rouvinski A, Gahali-Sass I, Stav I, Metzer E, Atlan H, Taraboulos A. Both raft- and non-raft proteins associate with CHAPS-insoluble complexes: some APP in large complexes. Biochem Biophys Res Commun 2003; 308:750-8. [PMID: 12927782 DOI: 10.1016/s0006-291x(03)01470-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Components of caveolae and lipid rafts are characterized by their buoyancy after detergent extraction. Using flotations in density gradients, we now show that non-raft membrane molecules are also associated with detergent-insoluble, buoyant assemblies. When Triton X-100 cellular extracts were spun to equilibrium in Nycodenz, only components of classical rafts floated. In contrast, with the zwitterionic detergent CHAPS, non-raft residents such as calnexin and APP also buoyed. When CHAPS extracts were spun in non-equilibrium (velocity) conditions, some raft components rapidly exited the input fractions while other raft markers and non-raft molecules remained relatively immobile. This pointed to size heterogeneities of CHAPS-insoluble complexes. Combined velocity/equilibrium gradients broadly divided CHAPS-insoluble membrane complexes into three size categories, which all contained cholesterol and the glycosphingolipid GM1. Large complexes were enriched in caveolin and ESA. Medium size complexes were enriched in PrP, whereas small complexes contained non-raft proteins, PrP, and some ESA. While Alzheimer's APP was primarily confined to small assemblies, a portion of its glycosylated form did buoy with large complexes. Large CHAPS-insoluble complexes resemble, but are not equal to, classical rafts. These findings extend considerably the range of detergent-insoluble membranal domains.
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Affiliation(s)
- Alexander Rouvinski
- Department of Molecular Biology, The Hebrew University-Hadassah Medical School, P.O. Box 12272, Jerusalem 91120, Israel
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Beddoe T, Lithgow T. Delivery of nascent polypeptides to the mitochondrial surface. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1592:35-9. [PMID: 12191766 DOI: 10.1016/s0167-4889(02)00262-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Thousands of polypeptides with diverse biochemical properties, some of which are extremely hydrophobic, are targeted from cytoplasmic ribosomes to the surface of mitochondria. Localised synthesis, as well as transient interactions with a wide array of molecular chaperones and other cytoplasmic factors, can promote productive interaction of mitochondrial proteins with the TOM complex to initiate protein import into mitochondria.
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Affiliation(s)
- Travis Beddoe
- Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia
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