Articles de revues : « COQ4 »

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Yen, Hsiu-Chuan, Bing-Shian Chen, Si-Ling Yang, Shin-Yu Wu, Chun-Wei Chang, Kuo-Chen Wei, Jee-Ching Hsu, Yung-Hsing Hsu, Tzung-Hai Yen et Chih-Lung Lin. « Levels of Coenzyme Q10 and Several COQ Proteins in Human Astrocytoma Tissues Are Inversely Correlated with Malignancy ». Biomolecules 12, n^o 2 (20 février 2022) : 336. http://dx.doi.org/10.3390/biom12020336.

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In a previous study, we reported the alterations of primary antioxidant enzymes and decreased citrate synthase (CS) activities in different grades of human astrocytoma tissues. Here, we further investigated coenzyme Q10 (CoQ10) levels and protein levels of polyprenyl diphosphate synthase subunit (PDSS2) and several COQ proteins required for CoQ10 biosynthesis in these tissues. We found that the level of endogenous CoQ10, but not of exogenous α-tocopherol, was higher in nontumor controls than in all grades of astrocytoma tissues. The levels of COQ3, COQ5, COQ6, COQ7, COQ8A, and COQ9, but not of COQ4, were lower in Grade IV astrocytoma tissues than in controls or low-grade (Grades I and II) astrocytomas, but PDSS2 levels were higher in astrocytoma tissues than in controls. Correlation analysis revealed that the levels of CoQ10 and COQ proteins were negatively correlated with malignancy degree and positively correlated with CS activity, whereas PDSS2 level was positively correlated with malignancy. Moreover, lower level of mitochondrial DNA-encoded cytochrome c oxidase subunit 2 was not only associated with a higher malignancy degree but also with lower level of all COQ proteins detected. The results revealed that mitochondrial abnormalities are associated with impaired CoQ10 maintenance in human astrocytoma progression.

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Gomes, Fernando, Erich B. Tahara, Cleverson Busso, Alicia J. Kowaltowski et Mario H. Barros. « nde1 deletion improves mitochondrial DNA maintenance in Saccharomyces cerevisiae coenzyme Q mutants ». Biochemical Journal 449, n^o 3 (9 janvier 2013) : 595–603. http://dx.doi.org/10.1042/bj20121432.

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Saccharomyces cerevisiae has three distinct inner mitochondrial membrane NADH dehydrogenases mediating the transfer of electrons from NADH to CoQ (coenzyme Q): Nde1p, Nde2p and Ndi1p. The active site of Ndi1p faces the matrix side, whereas the enzymatic activities of Nde1p and Nde2p are restricted to the intermembrane space side, where they are responsible for cytosolic NADH oxidation. In the present study we genetically manipulated yeast strains in order to alter the redox state of CoQ and NADH dehydrogenases to evaluate the consequences on mtDNA (mitochondrial DNA) maintenance. Interestingly, nde1 deletion was protective for mtDNA in strains defective in CoQ function. Additionally, the absence of functional Nde1p promoted a decrease in the rate of H2O2 release in isolated mitochondria from different yeast strains. On the other hand, overexpression of the predominant NADH dehydrogenase NDE1 elevated the rate of mtDNA loss and was toxic to coq10 and coq4 mutants. Increased CoQ synthesis through COQ8 overexpression also demonstrated that there is a correlation between CoQ respiratory function and mtDNA loss: supraphysiological CoQ levels were protective against mtDNA loss in the presence of oxidative imbalance generated by Nde1p excess or exogenous H2O2. Altogether, our results indicate that impairment in the oxidation of cytosolic NADH by Nde1p is deleterious towards mitochondrial biogenesis due to an increase in reactive oxygen species release.

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Chen, Fengxiang, et Lei Yang. « The Transition Metal and Non-metal co-Doping Graphene for Oxygen Reduction Reaction Electrocatalysis : a Density Functional Theory Study ». Bulletin of Science and Practice 7, n^o 2 (15 février 2021) : 197–207. http://dx.doi.org/10.33619/2414-2948/63/18.

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Proton exchange membrane fuel cells (PEMFCs) are vital energy-conversion devices in a hydrogen-fueled economic. In this study, we performed density functional theory (DFT) calculations to study 4e− oxygen reduction reaction process on transition metal embedded in single and double vacancies (SV and DV) in a graphene. We calculated bonding energy and adsorption energy on CoX3 (X = B, C, N, Si, P and S) and CoX4 (X = B, C, N, Si, P and S) embedded in graphene. Our DFT results indicate that formation of CoX3 is unfeasible and the formation of CoX4 is feasible. In addition, the crucial role of ligand atoms near embedded metal atoms is revealed via the molecular orbital theory. Then the Gibbs free energy of CoX4 are calculated and the CoN4, CoS4, and CoP4 are predicted to be active for catalyzing ORR, and these also show ligand atoms’ coordination effect for catalytic activity of central metal. Furthermore, we observed that they have identical rate-determining step (RDS). This work can provide some references for transition atoms catalytic doped in carbon materials.

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Finsterer, Josef, et Sinda Zarrouk-Mahjoub. « Mitochondrial cardioencephalopathy due to a COQ4 mutation ». Molecular Genetics and Metabolism Reports 13 (décembre 2017) : 7–8. http://dx.doi.org/10.1016/j.ymgmr.2017.07.003.

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Marbois, Beth, Peter Gin, Kym F. Faull, Wayne W. Poon, Peter T. Lee, Jeff Strahan, Jennifer N. Shepherd et Catherine F. Clarke. « Coq3 and Coq4 Define a Polypeptide Complex in Yeast Mitochondria for the Biosynthesis of Coenzyme Q ». Journal of Biological Chemistry 280, n^o 21 (25 mars 2005) : 20231–38. http://dx.doi.org/10.1074/jbc.m501315200.

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Wang, Sining, Akash Jain, Noelle Alexa Novales, Audrey N. Nashner, Fiona Tran et Catherine F. Clarke. « Predicting and Understanding the Pathology of Single Nucleotide Variants in Human COQ Genes ». Antioxidants 11, n^o 12 (22 novembre 2022) : 2308. http://dx.doi.org/10.3390/antiox11122308.

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Coenzyme Q (CoQ) is a vital lipid that functions as an electron carrier in the mitochondrial electron transport chain and as a membrane-soluble antioxidant. Deficiencies in CoQ lead to metabolic diseases with a wide range of clinical manifestations. There are currently few treatments that can slow or stop disease progression. Primary CoQ10 deficiency can arise from mutations in any of the COQ genes responsible for CoQ biosynthesis. While many mutations in these genes have been identified, the clinical significance of most of them remains unclear. Here we analyzed the structural and functional impact of 429 human missense single nucleotide variants (SNVs) that give rise to amino acid substitutions in the conserved and functional regions of human genes encoding a high molecular weight complex known as the CoQ synthome (or Complex Q), consisting of the COQ3–COQ7 and COQ9 gene products. Using structures of COQ polypeptides, close homologs, and AlphaFold models, we identified 115 SNVs that are potentially pathogenic. Further biochemical characterizations in model organisms such as Saccharomyces cerevisiae are required to validate the pathogenicity of the identified SNVs. Collectively, our results will provide a resource for clinicians during patient diagnosis and guide therapeutic efforts toward combating primary CoQ10 deficiency.

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Basselin, Mireille, Shannon M. Hunt, Hiam Abdala-Valencia et Edna S. Kaneshiro. « Ubiquinone Synthesis in Mitochondrial and Microsomal Subcellular Fractions of Pneumocystis spp. : Differential Sensitivities to Atovaquone ». Eukaryotic Cell 4, n^o 8 (août 2005) : 1483–92. http://dx.doi.org/10.1128/ec.4.8.1483-1492.2005.

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ABSTRACT The lung pathogen Pneumocystis spp. is the causative agent of a type of pneumonia that can be fatal in people with defective immune systems, such as AIDS patients. Atovaquone, an analog of ubiquinone (coenzyme Q [CoQ]), inhibits mitochondrial electron transport and is effective in clearing mild to moderate cases of the infection. Purified rat-derived intact Pneumocystis carinii cells synthesize de novo four CoQ homologs, CoQ7, CoQ8, CoQ9, and CoQ10, as demonstrated by the incorporation of radiolabeled precursors of both the benzoquinone ring and the polyprenyl chain. A central step in CoQ biosynthesis is the condensation of p-hydroxybenzoic acid (PHBA) with a long-chain polyprenyl diphosphate molecule. In the present study, CoQ biosynthesis was evaluated by the incorporation of PHBA into completed CoQ molecules using P. carinii cell-free preparations. CoQ synthesis in whole-cell homogenates was not affected by the respiratory inhibitors antimycin A and dicyclohexylcarbodiimide but was diminished by atovaquone. Thus, atovaquone has inhibitory activity on both electron transport and CoQ synthesis in this pathogen. Furthermore, both the mitochondrial and microsomal fractions were shown to synthesize de novo all four P. carinii CoQ homologs. Interestingly, atovaquone inhibited microsomal CoQ synthesis, whereas it had no effect on mitochondrial CoQ synthesis. This is the first pathogenic eukaryotic microorganism in which biosynthesis of CoQ molecules from the initial PHBA:polyprenyl transferase reaction has been unambiguously shown to occur in two distinct compartments of the same cell.

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Spinazzi, Marco, Enrico Radaelli, Katrien Horré, Amaia M. Arranz, Natalia V. Gounko, Patrizia Agostinis, Teresa Mendes Maia et al. « PARL deficiency in mouse causes Complex III defects, coenzyme Q depletion, and Leigh-like syndrome ». Proceedings of the National Academy of Sciences 116, n^o 1 (21 décembre 2018) : 277–86. http://dx.doi.org/10.1073/pnas.1811938116.

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The mitochondrial intramembrane rhomboid protease PARL has been implicated in diverse functions in vitro, but its physiological role in vivo remains unclear. Here we show that Parl ablation in mouse causes a necrotizing encephalomyelopathy similar to Leigh syndrome, a mitochondrial disease characterized by disrupted energy production. Mice with conditional PARL deficiency in the nervous system, but not in muscle, develop a similar phenotype as germline Parl KOs, demonstrating the vital role of PARL in neurological homeostasis. Genetic modification of two major PARL substrates, PINK1 and PGAM5, do not modify this severe neurological phenotype. Parl−/− brain mitochondria are affected by progressive ultrastructural changes and by defects in Complex III (CIII) activity, coenzyme Q (CoQ) biosynthesis, and mitochondrial calcium metabolism. PARL is necessary for the stable expression of TTC19, which is required for CIII activity, and of COQ4, which is essential in CoQ biosynthesis. Thus, PARL plays a previously overlooked constitutive role in the maintenance of the respiratory chain in the nervous system, and its deficiency causes progressive mitochondrial dysfunction and structural abnormalities leading to neuronal necrosis and Leigh-like syndrome.

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Sondheimer, Neal, Stacy Hewson, Jessie M. Cameron, Gino R. Somers, Jane Dunning Broadbent, Marcello Ziosi, Catarina Maria Quinzii et Ali B. Naini. « Novel recessive mutations in COQ4 cause severe infantile cardiomyopathy and encephalopathy associated with CoQ 10 deficiency ». Molecular Genetics and Metabolism Reports 12 (septembre 2017) : 23–27. http://dx.doi.org/10.1016/j.ymgmr.2017.05.001.

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Caglayan, Ahmet Okay, Hakan Gumus, Erin Sandford, Thomas L. Kubisiak, Qianyi Ma, A. Bilge Ozel, Huseyin Per, Jun Z. Li, Vikram G. Shakkottai et Margit Burmeister. « COQ4 Mutation Leads to Childhood-Onset Ataxia Improved by CoQ10 Administration ». Cerebellum 18, n^o 3 (8 mars 2019) : 665–69. http://dx.doi.org/10.1007/s12311-019-01011-x.

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Belogrudov, Grigory I., Peter T. Lee, Tanya Jonassen, Adam Y. Hsu, Peter Gin et Catherine F. Clarke. « Yeast COQ4 Encodes a Mitochondrial Protein Required for Coenzyme Q Synthesis ». Archives of Biochemistry and Biophysics 392, n^o 1 (août 2001) : 48–58. http://dx.doi.org/10.1006/abbi.2001.2448.

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Meza-Torres, Catherine, Juan Diego Hernández-Camacho, Ana Belén Cortés-Rodríguez, Luis Fang, Tung Bui Thanh, Elisabet Rodríguez-Bies, Plácido Navas et Guillermo López-Lluch. « Resveratrol Regulates the Expression of Genes Involved in CoQ Synthesis in Liver in Mice Fed with High Fat Diet ». Antioxidants 9, n^o 5 (15 mai 2020) : 431. http://dx.doi.org/10.3390/antiox9050431.

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Resveratrol (RSV) is a bioactive natural molecule that induces antioxidant activity and increases protection against oxidative damage. RSV could be used to mitigate damages associated to metabolic diseases and aging. Particularly, RSV regulates different aspects of mitochondrial metabolism. However, no information is available about the effects of RSV on Coenzyme Q (CoQ), a central component in the mitochondrial electron transport chain. Here, we report for the first time that RSV modulates COQ genes and parameters associated to metabolic syndrome in mice. Mice fed with high fat diet (HFD) presented a higher weight gain, triglycerides (TGs) and cholesterol levels while RSV reverted TGs to control level but not weight or cholesterol. HFD induced a decrease of COQs gene mRNA level, whereas RSV reversed this decrease in most of the COQs genes. However, RSV did not show effect on CoQ9, CoQ10 and total CoQ levels, neither in CoQ-dependent antioxidant enzymes. HFD influenced mitochondrial dynamics and mitophagy markers. RSV modulated the levels of PINK1 and PARKIN and their ratio, indicating modulation of mitophagy. In summary, we report that RSV influences some of the metabolic adaptations of HFD affecting mitochondrial physiology while also regulates COQs gene expression levels in a process that can be associated with mitochondrial dynamics and turnover.

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Ling, Tsz-ki, Chun-yiu Law, Chun-hung Ko, Nai-chung Fong, Ka-chung Wong, Ka-lok Lee, Winnie Chiu-wing Chu, Gloria Brea-Calvo et Ching-wan Lam. « A common COQ4 mutation in undiagnosed mitochondrial disease : a local case series ». Pathology 51 (février 2019) : S112—S113. http://dx.doi.org/10.1016/j.pathol.2018.12.317.

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Casarin, Alberto, Jose Carlos Jimenez-Ortega, Eva Trevisson, Vanessa Pertegato, Mara Doimo, Maria Lara Ferrero-Gomez, Sara Abbadi et al. « Functional characterization of human COQ4, a gene required for Coenzyme Q10 biosynthesis ». Biochemical and Biophysical Research Communications 372, n^o 1 (juillet 2008) : 35–39. http://dx.doi.org/10.1016/j.bbrc.2008.04.172.

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Brea-Calvo, Gloria, Tobias B. Haack, Daniela Karall, Akira Ohtake, Federica Invernizzi, Rosalba Carrozzo, Laura Kremer et al. « COQ4 Mutations Cause a Broad Spectrum of Mitochondrial Disorders Associated with CoQ10 Deficiency ». American Journal of Human Genetics 96, n^o 2 (février 2015) : 309–17. http://dx.doi.org/10.1016/j.ajhg.2014.12.023.

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Marbois, Beth, Peter Gin, Melissa Gulmezian et Catherine F. Clarke. « The yeast Coq4 polypeptide organizes a mitochondrial protein complex essential for coenzyme Q biosynthesis ». Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1791, n^o 1 (janvier 2009) : 69–75. http://dx.doi.org/10.1016/j.bbalip.2008.10.006.

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FORSGREN, Margareta, Anneli ATTERSAND, Staffan LAKE, Jacob GRÜNLER, Ewa SWIEZEWSKA, Gustav DALLNER et Isabel CLIMENT. « Isolation and functional expression of human COQ2, a gene encoding a polyprenyl transferase involved in the synthesis of CoQ ». Biochemical Journal 382, n^o 2 (24 août 2004) : 519–26. http://dx.doi.org/10.1042/bj20040261.

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The COQ2 gene in Saccharomyces cerevisiae encodes a Coq2 (p-hydroxybenzoate:polyprenyl transferase), which is required in the biosynthetic pathway of CoQ (ubiquinone). This enzyme catalyses the prenylation of p-hydroxybenzoate with an all-trans polyprenyl group. We have isolated cDNA which we believe encodes the human homologue of COQ2 from a human muscle and liver cDNA library. The clone contained an open reading frame of length 1263 bp, which encodes a polypeptide that has sequence homology with the Coq2 homologues in yeast, bacteria and mammals. The human COQ2 gene, when expressed in yeast Coq2 null mutant cells, rescued the growth of this yeast strain in the absence of a non-fermentable carbon source and restored CoQ biosynthesis. However, the rate of CoQ biosynthesis in the rescued cells was lower when compared with that in cells rescued with the yeast COQ2 gene. CoQ formed when cells were incubated with labelled decaprenyl pyrophosphate and nonaprenyl pyrophosphate, showing that the human enzyme is active and that it participates in the biosynthesis of CoQ.

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Martín-Montalvo, Alejandro, Isabel González-Mariscal, Sergio Padilla, Manuel Ballesteros, David L. Brautigan, Plácido Navas et Carlos Santos-Ocaña. « Respiratory-induced coenzyme Q biosynthesis is regulated by a phosphorylation cycle of Cat5p/Coq7p ». Biochemical Journal 440, n^o 1 (27 octobre 2011) : 107–14. http://dx.doi.org/10.1042/bj20101422.

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CoQ6 (coenzyme Q6) biosynthesis in yeast is a well-regulated process that requires the final conversion of the late intermediate DMQ6 (demethoxy-CoQ6) into CoQ6 in order to support respiratory metabolism in yeast. The gene CAT5/COQ7 encodes the Cat5/Coq7 protein that catalyses the hydroxylation step of DMQ6 conversion into CoQ6. In the present study, we demonstrated that yeast Coq7 recombinant protein purified in bacteria can be phosphorylated in vitro using commercial PKA (protein kinase A) or PKC (protein kinase C) at the predicted amino acids Ser20, Ser28 and Thr32. The total absence of phosphorylation in a Coq7p version containing alanine instead of these phospho-amino acids, the high extent of phosphorylation produced and the saturated conditions maintained in the phosphorylation assay indicate that probably no other putative amino acids are phosphorylated in Coq7p. Results from in vitro assays have been corroborated using phosphorylation assays performed in purified mitochondria without external or commercial kinases. Coq7p remains phosphorylated in fermentative conditions and becomes dephosphorylated when respiratory metabolism is induced. The substitution of phosphorylated residues to alanine dramatically increases CoQ6 levels (256%). Conversely, substitution with negatively charged residues decreases CoQ6 content (57%). These modifications produced in Coq7p also alter the ratio between DMQ6 and CoQ6 itself, indicating that the Coq7p phosphorylation state is a regulatory mechanism for CoQ6 synthesis.

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Bosch, Annet M., Erik-Jan Kamsteeg, Richard J. Rodenburg, Arend W. van Deutekom, Dennis R. Buis, Marc Engelen et Jan-Maarten Cobben. « Coenzyme Q10 deficiency due to a COQ4 gene defect causes childhood-onset spinocerebellar ataxia and stroke-like episodes ». Molecular Genetics and Metabolism Reports 17 (décembre 2018) : 19–21. http://dx.doi.org/10.1016/j.ymgmr.2018.09.002.

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Acosta Lopez, Manuel J., Eva Trevisson, Marcella Canton, Luis Vazquez-Fonseca, Valeria Morbidoni, Elisa Baschiera, Chiara Frasson et al. « Vanillic Acid Restores Coenzyme Q Biosynthesis and ATP Production in Human Cells Lacking COQ6 ». Oxidative Medicine and Cellular Longevity 2019 (10 juillet 2019) : 1–11. http://dx.doi.org/10.1155/2019/3904905.

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Coenzyme Q (CoQ), a redox-active lipid, is comprised of a quinone group and a polyisoprenoid tail. It is an electron carrier in the mitochondrial respiratory chain, a cofactor of other mitochondrial dehydrogenases, and an essential antioxidant. CoQ requires a large set of enzymes for its biosynthesis; mutations in genes encoding these proteins cause primary CoQ deficiency, a clinically and genetically heterogeneous group of diseases. Patients with CoQ deficiency often respond to oral CoQ10 supplementation. Treatment is however problematic because of the low bioavailability of CoQ10 and the poor tissue delivery. In recent years, bypass therapy using analogues of the precursor of the aromatic ring of CoQ has been proposed as a promising alternative. We have previously shown using a yeast model that vanillic acid (VA) can bypass mutations of COQ6, a monooxygenase required for the hydroxylation of the C5 carbon of the ring. In this work, we have generated a human cell line lacking functional COQ6 using CRISPR/Cas9 technology. We show that these cells cannot synthesize CoQ and display severe ATP deficiency. Treatment with VA can recover CoQ biosynthesis and ATP production. Moreover, these cells display increased ROS production, which is only partially corrected by exogenous CoQ, while VA restores ROS to normal levels. Furthermore, we show that these cells accumulate 3-decaprenyl-1,4-benzoquinone, suggesting that in mammals, the decarboxylation and C1 hydroxylation reactions occur before or independently of the C5 hydroxylation. Finally, we show that COQ6 isoform c (transcript NM_182480) does not encode an active enzyme. VA can be produced in the liver by the oxidation of vanillin, a nontoxic compound commonly used as a food additive, and crosses the blood-brain barrier. These characteristics make it a promising compound for the treatment of patients with CoQ deficiency due to COQ6 mutations.

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Nishida, Ikuhisa, Ryota Yanai, Yasuhiro Matsuo, Tomohiro Kaino et Makoto Kawamukai. « Benzoic acid inhibits Coenzyme Q biosynthesis in Schizosaccharomyces pombe ». PLOS ONE 15, n^o 11 (24 novembre 2020) : e0242616. http://dx.doi.org/10.1371/journal.pone.0242616.

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Coenzyme Q (CoQ, ubiquinone) is an essential component of the electron transport system in aerobic organisms. Human type CoQ10, which has 10 units of isoprene in its quinone structure, is especially valuable as a food supplement. Therefore, studying the biosynthesis of CoQ10 is important not only for increasing metabolic knowledge, but also for improving biotechnological production. Herein, we show that Schizosaccharomyces pombe utilizes p-aminobenzoate (PABA) in addition to p-hydroxybenzoate (PHB) as a precursor for CoQ10 synthesis. We explored compounds that affect the synthesis of CoQ10 and found benzoic acid (Bz) at >5 μg/mL inhibited CoQ biosynthesis without accumulation of apparent CoQ intermediates. This inhibition was counteracted by incubation with a 10-fold lower amount of PABA or PHB. Overexpression of PHB-polyprenyl transferase encoded by ppt1 (coq2) also overcame the inhibition of CoQ biosynthesis by Bz. Inhibition by Bz was efficient in S. pombe and Schizosaccharomyces japonicus, but less so in Saccharomyces cerevisiae, Aureobasidium pullulans, and Escherichia coli. Bz also inhibited a S. pombe ppt1 (coq2) deletion strain expressing human COQ2, and this strain also utilized PABA as a precursor of CoQ10. Thus, Bz is likely to inhibit prenylation reactions involving PHB or PABA catalyzed by Coq2.

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Burgardt, Arthur, Ludovic Pelosi, Mahmoud Hajj Chehade, Volker F. Wendisch et Fabien Pierrel. « Rational Engineering of Non-Ubiquinone Containing Corynebacterium glutamicum for Enhanced Coenzyme Q10 Production ». Metabolites 12, n^o 5 (11 mai 2022) : 428. http://dx.doi.org/10.3390/metabo12050428.

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Coenzyme Q10 (CoQ10) is a lipid-soluble compound with important physiological functions and is sought after in the food and cosmetic industries owing to its antioxidant properties. In our previous proof of concept, we engineered for CoQ10 biosynthesis the industrially relevant Corynebacterium glutamicum, which does not naturally synthesize any CoQ. Here, liquid chromatography–mass spectrometry (LC–MS) analysis identified two metabolic bottlenecks in the CoQ10 production, i.e., low conversion of the intermediate 10-prenylphenol (10P-Ph) to CoQ10 and the accumulation of isoprenologs with prenyl chain lengths of not only 10, but also 8 to 11 isopentenyl units. To overcome these limitations, the strain was engineered for expression of the Ubi complex accessory factors UbiJ and UbiK from Escherichia coli to increase flux towards CoQ10, and by replacement of the native polyprenyl diphosphate synthase IspB with a decaprenyl diphosphate synthase (DdsA) to select for prenyl chains with 10 isopentenyl units. The best strain UBI6-Rs showed a seven-fold increased CoQ10 content and eight-fold increased CoQ10 titer compared to the initial strain UBI4-Pd, while the abundance of CoQ8, CoQ9, and CoQ11 was significantly reduced. This study demonstrates the application of the recent insight into CoQ biosynthesis to improve metabolic engineering of a heterologous CoQ10 production strain.

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Eisenberg-Bord, Michal, Hui S. Tsui, Diana Antunes, Lucía Fernández-del-Río, Michelle C. Bradley, Cory D. Dunn, Theresa P. T. Nguyen, Doron Rapaport, Catherine F. Clarke et Maya Schuldiner. « The Endoplasmic Reticulum-Mitochondria Encounter Structure Complex Coordinates Coenzyme Q Biosynthesis ». Contact 2 (janvier 2019) : 251525641882540. http://dx.doi.org/10.1177/2515256418825409.

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Loss of the endoplasmic reticulum (ER)-mitochondria encounter structure (ERMES) complex that resides in contact sites between the yeast ER and mitochondria leads to impaired respiration; however, the reason for that is not clear. We find that in ERMES null mutants, there is an increase in the level of mRNAs encoding for biosynthetic enzymes of coenzyme Q6 (CoQ6), an essential electron carrier of the mitochondrial respiratory chain. We show that the mega complexes involved in CoQ6 biosynthesis (CoQ synthomes) are destabilized in ERMES mutants. This, in turn, affects the level and distribution of CoQ6 within the cell, resulting in reduced mitochondrial CoQ6. We suggest that these outcomes contribute to the reduced respiration observed in ERMES mutants. Fluorescence microscopy experiments demonstrate close proximity between the CoQ synthome and ERMES, suggesting a spatial coordination. The involvement of the ER-mitochondria contact site in regulation of CoQ6 biogenesis highlights an additional level of communication between these two organelles.

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Awad, Agape M., Michelle C. Bradley, Lucía Fernández-del-Río, Anish Nag, Hui S. Tsui et Catherine F. Clarke. « Coenzyme Q10 deficiencies : pathways in yeast and humans ». Essays in Biochemistry 62, n^o 3 (6 juillet 2018) : 361–76. http://dx.doi.org/10.1042/ebc20170106.

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Coenzyme Q (ubiquinone or CoQ) is an essential lipid that plays a role in mitochondrial respiratory electron transport and serves as an important antioxidant. In human and yeast cells, CoQ synthesis derives from aromatic ring precursors and the isoprene biosynthetic pathway. Saccharomyces cerevisiae coq mutants provide a powerful model for our understanding of CoQ biosynthesis. This review focusses on the biosynthesis of CoQ in yeast and the relevance of this model to CoQ biosynthesis in human cells. The COQ1–COQ11 yeast genes are required for efficient biosynthesis of yeast CoQ. Expression of human homologs of yeast COQ1–COQ10 genes restore CoQ biosynthesis in the corresponding yeast coq mutants, indicating profound functional conservation. Thus, yeast provides a simple yet effective model to investigate and define the function and possible pathology of human COQ (yeast or human gene involved in CoQ biosynthesis) gene polymorphisms and mutations. Biosynthesis of CoQ in yeast and human cells depends on high molecular mass multisubunit complexes consisting of several of the COQ gene products, as well as CoQ itself and CoQ intermediates. The CoQ synthome in yeast or Complex Q in human cells, is essential for de novo biosynthesis of CoQ. Although some human CoQ deficiencies respond to dietary supplementation with CoQ, in general the uptake and assimilation of this very hydrophobic lipid is inefficient. Simple natural products may serve as alternate ring precursors in CoQ biosynthesis in both yeast and human cells, and these compounds may act to enhance biosynthesis of CoQ or may bypass certain deficient steps in the CoQ biosynthetic pathway.

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Widmeier, Eugen, Merlin Airik, Hannah Hugo, David Schapiro, Johannes Wedel, Chandra C. Ghosh, Makiko Nakayama et al. « Treatment with 2,4-Dihydroxybenzoic Acid Prevents FSGS Progression and Renal Fibrosis in Podocyte-Specific Coq6 Knockout Mice ». Journal of the American Society of Nephrology 30, n^o 3 (8 février 2019) : 393–405. http://dx.doi.org/10.1681/asn.2018060625.

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BackgroundAlthough studies have identified >55 genes as causing steroid-resistant nephrotic syndrome (SRNS) and localized its pathogenesis to glomerular podocytes, the disease mechanisms of SRNS remain largely enigmatic. We recently reported that individuals with mutations in COQ6, a coenzyme Q (also called CoQ10, CoQ, or ubiquinone) biosynthesis pathway enzyme, develop SRNS with sensorineural deafness, and demonstrated the beneficial effect of CoQ for maintenace of kidney function.MethodsTo study COQ6 function in podocytes, we generated a podocyte-specific Coq6 knockout mouse (Coq6podKO) model and a transient siRNA-based COQ6 knockdown in a human podocyte cell line. Mice were monitored for development of proteinuria and assessed for development of glomerular sclerosis. Using a podocyte migration assay, we compared motility in COQ6 knockdown podocytes and control podocytes. We also randomly assigned 5-month-old Coq6podKO mice and controls to receive no treatment or 2,4-dihydroxybenzoic acid (2,4-diHB), an analog of a CoQ precursor molecule that is classified as a food additive by health authorities in Europe and the United States.ResultsAbrogation of Coq6 in mouse podocytes caused FSGS and proteinuria (>46-fold increases in albuminuria). In vitro studies revealed an impaired podocyte migration rate in COQ6 knockdown human podocytes. Treating Coq6podKO mice or cells with 2,4-diHB prevented renal dysfunction and reversed podocyte migration rate impairment. Survival of Coq6podKO mice given 2,4diHB was comparable to that of control mice and significantly higher than that of untreated Coq6podKO mice, half of which died by 10 months of age.ConclusionsThese findings reveal a potential novel treatment strategy for those cases of human nephrotic syndrome that are caused by a primary dysfunction in the CoQ10 biosynthesis pathway.

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Dai, Ya-Nan, Kang Zhou, Dong-Dong Cao, Yong-Liang Jiang, Fei Meng, Chang-Biao Chi, Yan-Min Ren, Yuxing Chen et Cong-Zhao Zhou. « Crystal structures and catalytic mechanism of theC-methyltransferase Coq5 provide insights into a key step of the yeast coenzyme Q synthesis pathway ». Acta Crystallographica Section D Biological Crystallography 70, n^o 8 (25 juillet 2014) : 2085–92. http://dx.doi.org/10.1107/s1399004714011559.

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Saccharomyces cerevisiaeCoq5 is anS-adenosyl methionine (SAM)-dependent methyltransferase (SAM-MTase) that catalyzes the onlyC-methylation step in the coenzyme Q (CoQ) biosynthesis pathway, in which 2-methoxy-6-polyprenyl-1,4-benzoquinone (DDMQH2) is converted to 2-methoxy-5-methyl-6-polyprenyl-1,4-benzoquinone (DMQH2). Crystal structures of Coq5 were determined in the apo form (Coq5-apo) at 2.2 Å resolution and in the SAM-bound form (Coq5-SAM) at 2.4 Å resolution, representing the first pair of structures for the yeast CoQ biosynthetic enzymes. Coq5 displays a typical class I SAM-MTase structure with two minor variations beyond the core domain, both of which are considered to participate in dimerization and/or substrate recognition. Slight conformational changes at the active-site pocket were observed upon binding of SAM. Structure-based computational simulation using an analogue of DDMQH2enabled us to identify the binding pocket and entrance tunnel of the substrate. Multiple-sequence alignment showed that the residues contributing to the dimeric interface and the SAM- and DDMQH2-binding sites are highly conserved in Coq5 and homologues from diverse species. A putative catalytic mechanism of Coq5 was proposed in which Arg201 acts as a general base to initiate catalysis with the help of a water molecule.

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Berenguel Hernández, Aida M., Mercedes de la Cruz, María Alcázar-Fabra, Andrés Prieto-Rodríguez, Ana Sánchez-Cuesta, Jesús Martin, José R. Tormo et al. « Design of High-Throughput Screening of Natural Extracts to Identify Molecules Bypassing Primary Coenzyme Q Deficiency in Saccharomyces cerevisiae ». SLAS DISCOVERY : Advancing the Science of Drug Discovery 25, n^o 3 (21 novembre 2019) : 299–309. http://dx.doi.org/10.1177/2472555219877185.

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Coenzyme Q10 (CoQ10) deficiency syndrome is a rare disease included in the family of mitochondrial diseases, which is a heterogeneous group of genetic disorders characterized by defective energy production. CoQ10 biosynthesis in humans requires at least 11 gene products acting in a multiprotein complex within mitochondria. The high-throughput screening (HTS) method based on the stabilization of the CoQ biosynthesis complex (Q-synthome) produced by the COQ8 gene overexpression is proven here to be a successful method for identifying new molecules from natural extracts that are able to bypass the CoQ6 deficiency in yeast mutant cells. The main features of the new approach are the combination of two yeast targets defective in genes with different functions on CoQ6 biosynthesis to secure the versatility of the molecule identified, the use of glycerol as a nonfermentable carbon source providing a wide growth window, and the stringent conditions required to mark an extract as positive. The application of this pilot approach to a representative subset of 1200 samples of the Library of Natural Products of Fundación MEDINA resulted in the finding of nine positive extracts. The fractionation of three of the nine extracts allowed the identification of five molecules; two of them are present in molecule databases of natural extracts and three are nondescribed molecules. The use of this screening method opens the possibility of discovering molecules with CoQ10-bypassing action useful as therapeutic agents to fight against mitochondrial diseases in human patients.

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MacDonald, Michael J. « Stimulation of insulin release from pancreatic islets by quinones ». Bioscience Reports 11, n^o 3 (1 juin 1991) : 165–70. http://dx.doi.org/10.1007/bf01182485.

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Coenzyme Q (CoQ0) and other quinones were shown to be potent insulin secretagogues in the isolated pancreatic islet. The order of potency was CoQ0≅benzoquinone≅hydroquinonemenadione. CoQ6 and CoQ10 (ubiquinone), duroquinone and durohydroquinone did not stimulate insulin release. CoQ0's insulinotropism was enhanced in calcium-free medium and CoQ0 appeared to stimulate only the second phase of insulin release. CoQ0 inhibited inositol mono-, bis- and trisphosphate formation. Inhibitors of mitochondrial respiration (rotenone, antimycin A, FCCP and cyanide) and the calcium channel blocker verapamil, did not inhibit CoQ0-induced insulin release. Dicumarol, an inhibitor of quinone reductase, did not inhibit CoQ0-induced insulin release, but it did inhibit glucose-induced insulin release suggesting that the enzyme and quinones play a role in glucose-induced insulin release. Quinones may stimulate insulin release by mimicking physiologically-occuring quinones, such as CoQ10, by acting on the plasma membrane or in the cytosol. Exogenous quinones may bypass the quinone reductase reaction, as well as many reactions important for exocytosis.

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Zhou, Li, Gilles Barthe, Pierre-Yves Strub, Junyi Liu et Mingsheng Ying. « CoqQ : Foundational Verification of Quantum Programs ». Proceedings of the ACM on Programming Languages 7, POPL (9 janvier 2023) : 833–65. http://dx.doi.org/10.1145/3571222.

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CoqQ is a framework for reasoning about quantum programs in the Coq proof assistant. Its main components are: a deeply embedded quantum programming language, in which classic quantum algorithms are easily expressed, and an expressive program logic for proving properties of programs. CoqQ is foundational: the program logic is formally proved sound with respect to a denotational semantics based on state-of-art mathematical libraries (MathComp and MathComp Analysis). CoqQ is also practical: assertions can use Dirac expressions, which eases concise specifications, and proofs can exploit local and parallel reasoning, which minimizes verification effort. We illustrate the applicability of CoqQ with many examples from the literature.

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Bradley, Michelle C., Krista Yang, Lucía Fernández-del-Río, Jennifer Ngo, Anita Ayer, Hui S. Tsui, Noelle Alexa Novales et al. « COQ11 deletion mitigates respiratory deficiency caused by mutations in the gene encoding the coenzyme Q chaperone protein Coq10 ». Journal of Biological Chemistry 295, n^o 18 (23 mars 2020) : 6023–42. http://dx.doi.org/10.1074/jbc.ra119.012420.

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Coenzyme Q (Qn) is a vital lipid component of the electron transport chain that functions in cellular energy metabolism and as a membrane antioxidant. In the yeast Saccharomyces cerevisiae, coq1–coq9 deletion mutants are respiratory-incompetent, sensitive to lipid peroxidation stress, and unable to synthesize Q6. The yeast coq10 deletion mutant is also respiratory-deficient and sensitive to lipid peroxidation, yet it continues to produce Q6 at an impaired rate. Thus, Coq10 is required for the function of Q6 in respiration and as an antioxidant and is believed to chaperone Q6 from its site of synthesis to the respiratory complexes. In several fungi, Coq10 is encoded as a fusion polypeptide with Coq11, a recently identified protein of unknown function required for efficient Q6 biosynthesis. Because “fused” proteins are often involved in similar biochemical pathways, here we examined the putative functional relationship between Coq10 and Coq11 in yeast. We used plate growth and Seahorse assays and LC-MS/MS analysis to show that COQ11 deletion rescues respiratory deficiency, sensitivity to lipid peroxidation, and decreased Q6 biosynthesis of the coq10Δ mutant. Additionally, immunoblotting indicated that yeast coq11Δ mutants accumulate increased amounts of certain Coq polypeptides and display a stabilized CoQ synthome. These effects suggest that Coq11 modulates Q6 biosynthesis and that its absence increases mitochondrial Q6 content in the coq10Δcoq11Δ double mutant. This augmented mitochondrial Q6 content counteracts the respiratory deficiency and lipid peroxidation sensitivity phenotypes of the coq10Δ mutant. This study further clarifies the intricate connection between Q6 biosynthesis, trafficking, and function in mitochondrial metabolism.

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Zhou, Lian, Ming Li, Xing-Yu Wang, Hao Liu, Shuang Sun, Haifeng Chen, Alan Poplawsky et Ya-Wen He. « Biosynthesis of Coenzyme Q in the Phytopathogen Xanthomonas campestris via a Yeast-Like Pathway ». Molecular Plant-Microbe Interactions® 32, n^o 2 (février 2019) : 217–26. http://dx.doi.org/10.1094/mpmi-07-18-0183-r.

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Coenzyme Q (CoQ) is a lipid-soluble membrane component found in organisms ranging from bacteria to mammals. The biosynthesis of CoQ has been intensively studied in Escherichia coli, where 12 genes (ubiA, -B, -C, -D, -E, -F, -G, -H, -I, -J, -K, and -X) are involved. In this study, we first investigated the putative genes for CoQ8 biosynthesis in the phytopathogen Xanthomonas campestris pv. campestris using a combination of bioinformatic, genetic, and biochemical methods. We showed that Xc_0489 (coq7Xc) encodes a di-iron carboxylate monooxygenase filling the E. coli UbiF role for hydroxylation at C-6 of the aromatic ring. Xc_0233 (ubiJXc) encodes a novel protein with an E. coli UbiJ-like domain organization and is required for CoQ8 biosynthesis. The X. campestris pv. campestris decarboxylase gene remains unidentified. Further functional analysis showed that ubiB and ubiK homologs ubiBXc and ubiKXc are required for CoQ8 biosynthesis in X. campestris pv. campestris. Deletion of ubiJXc, ubiBXc, and ubiKXc led to the accumulation of an intermediate 3-octaprenyl-4-hydroxybenzoic acid. UbiKXc interacts with UbiJXc and UbiBXc to form a regulatory complex. Deletion analyses of these CoQ8 biosynthetic genes indicated that they are important for virulence in Chinese radish. These results suggest that the X. campestris pv. campestris CoQ8 biosynthetic reactions and regulatory mechanisms are divergent from those of E. coli. The variations provide an opportunity for the design of highly specific inhibitors for the prevention of infection by the phytopathogen X. campestris pv. campestris.

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Romero-Moya, Damià, Julio Castaño, Carlos Santos-Ocaña, Plácido Navas et Pablo Menendez. « Generation, genome edition and characterization of iPSC lines from a patient with coenzyme Q 10 deficiency harboring a heterozygous mutation in COQ4 gene ». Stem Cell Research 24 (octobre 2017) : 144–47. http://dx.doi.org/10.1016/j.scr.2016.09.007.

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Walker, Emma C., Elizabeth M. Todd, Rashmi Ramani, Edgar Anaya, Sarah Javati, John-Paul Matlam, William Pomat et Sharon Celeste Morley. « A novel variant in CoQ biosynthesis highly prevalent in Papua New Guinea children increases mortality following bacterial pneumonia ». Journal of Immunology 206, n^o 1_Supplement (1 mai 2021) : 52.20. http://dx.doi.org/10.4049/jimmunol.206.supp.52.20.

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Abstract To identify immune variants predisposing to severe pneumonia, we performed whole exome sequencing in a pediatric population highly susceptible to acute lower respiratory infections, identifying a candidate novel variant in the CoQ biosynthetic pathway. To evaluate the effect of this variant on immune function during bacterial pneumonia, we generated a mouse line using CRISPR-Cas9 that expresses the homologous variant in the enzyme COQ6. Interestingly, we found that the variant does not result in CoQ deficiency, as other known variants in biosynthetic proteins do, however intra-tracheal S. pneumoniae infection leads to increased bacteremia and mortality in mutant mice. Mechanistic studies show that mutant macrophages have reduced pneumococcal killing in vitro, showing an intrinsic defect in innate immune function conferred by the COQ6 mutation. Variant macrophages have decreased mitochondrial respiratory capacity both at baseline and following stimulation with LPS, as well as an inability to induce mitochondrial reactive oxygen species (mROS) in response to stimulation despite increased mROS at baseline. Thus, the novel variant in a CoQ biosynthetic enzyme leads to changes in macrophage mitochondrial function and an intrinsic inability to kill internalized bacteria. As alveolar macrophages are the first responders in the lung to bacterial challenge, the inability of these macrophages to mount a sufficient immune response leads to the observed increase in mortality following bacterial pneumonia. This work describes a novel susceptibility locus to severe childhood pneumonia, and also represents the first known pathogenic variant in a CoQ biosynthetic protein that does not cause pathology resulting from CoQ deficiency.

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Lapointe, Jérôme, Ying Wang, Eve Bigras et Siegfried Hekimi. « The submitochondrial distribution of ubiquinone affects respiration in long-lived Mclk1+/− mice ». Journal of Cell Biology 199, n^o 2 (8 octobre 2012) : 215–24. http://dx.doi.org/10.1083/jcb.201203090.

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Mclk1 (also known as Coq7) and Coq3 code for mitochondrial enzymes implicated in the biosynthetic pathway of ubiquinone (coenzyme Q or UQ). Mclk1+/− mice are long-lived but have dysfunctional mitochondria. This phenotype remains unexplained, as no changes in UQ content were observed in these mutants. By producing highly purified submitochondrial fractions, we report here that Mclk1+/− mice present a unique mitochondrial UQ profile that was characterized by decreased UQ levels in the inner membrane coupled with increased UQ in the outer membrane. Dietary-supplemented UQ10 was actively incorporated in both mitochondrial membranes, and this was sufficient to reverse mutant mitochondrial phenotypes. Further, although homozygous Coq3 mutants die as embryos like Mclk1 homozygous null mice, Coq3+/− mice had a normal lifespan and were free of detectable defects in mitochondrial function or ubiquinone distribution. These findings indicate that MCLK1 regulates both UQ synthesis and distribution within mitochondrial membranes.

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Finsterer, Josef, FulvioA Scorza, AnaC Fiorini, CarlaA Scorza et AntonioCarlos de Almeida. « Lethal neonatal CoQ deficiency due to a COQ9 variant ». Journal of Pediatric Neurosciences 13, n^o 2 (2018) : 286. http://dx.doi.org/10.4103/jpn.jpn_37_18.

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Hseu, You-Cheng, Yu-Fang Tseng, Sudhir Pandey, Sirjana Shrestha, Kai-Yuan Lin, Cheng-Wen Lin, Chuan-Chen Lee, Sheng-Teng Huang et Hsin-Ling Yang. « Coenzyme Q0 Inhibits NLRP3 Inflammasome Activation through Mitophagy Induction in LPS/ATP-Stimulated Macrophages ». Oxidative Medicine and Cellular Longevity 2022 (7 janvier 2022) : 1–15. http://dx.doi.org/10.1155/2022/4266214.

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Coenzyme Q (CoQ) analogs with a variable number of isoprenoid units have exhibited as anti-inflammatory as well as antioxidant molecules. Using novel quinone derivative CoQ0 (2,3-dimethoxy-5-methyl-1,4-benzoquinone, zero side chain isoprenoid), we studied its molecular activities against LPS/ATP-induced inflammation and redox imbalance in murine RAW264.7 macrophages. CoQ0’s non- or subcytotoxic concentration suppressed the NLRP3 inflammasome and procaspase-1 activation, followed by downregulation of IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages. Similarly, treatment of CoQ0 led to LC3-I/II accumulation and p62/SQSTM1 activation. An increase in the Beclin-1/Bcl-2 ratio and a decrease in the expression of phosphorylated PI3K/AKT, p70 S6 kinase, and mTOR showed that autophagy was activated. Besides, CoQ0 increased Parkin protein to recruit damaged mitochondria and induced mitophagy in LPS/ATP-stimulated RAW264.7 macrophages. CoQ0 inhibited LPS/ATP-stimulated ROS generation in RAW264.7 macrophages. Notably, when LPS/ATP-stimulated RAW264.7 macrophages were treated with CoQ0, Mito-TEMPO (a mitochondrial ROS inhibitor), or N-acetylcysteine (NAC, a ROS inhibitor), there was a significant reduction of LPS/ATP-stimulated NLRP3 inflammasome activation and IL1β expression. Interestingly, treatment with CoQ0 or Mito-TEMPO, but not NAC, significantly increased LPS/ATP-induced LC3-II accumulation indicating that mitophagy plays a key role in the regulation of CoQ0-inhibited NLRP3 inflammasome activation. Nrf2 knockdown significantly decreased IL1β expression in LPS/ATP-stimulated RAW264.7 macrophages suggesting that CoQ0 inhibited ROS-mediated NLRP3 inflammasome activation and IL1β expression was suppressed due to the Nrf2 activation. Hence, this study showed that CoQ0 might be a promising candidate for the therapeutics of inflammatory disorders due to its effective anti-inflammatory as well as antioxidant properties.

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Garcia-Corzo, L., M. Luna-Sanchez, C. Doerrier, J. A. Garcia, A. Guaras, R. Acin-Perez, J. Bullejos-Peregrin et al. « Dysfunctional Coq9 protein causes predominant encephalomyopathy associated with CoQ deficiency ». Human Molecular Genetics 22, n^o 6 (18 décembre 2012) : 1233–48. http://dx.doi.org/10.1093/hmg/dds530.

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Wang, Wenping, Irene Liparulo, Nicola Rizzardi, Paola Bolignano, Natalia Calonghi, Christian Bergamini et Romana Fato. « Coenzyme Q Depletion Reshapes MCF-7 Cells Metabolism ». International Journal of Molecular Sciences 22, n^o 1 (28 décembre 2020) : 198. http://dx.doi.org/10.3390/ijms22010198.

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Mitochondrial dysfunction plays a significant role in the metabolic flexibility of cancer cells. This study aimed to investigate the metabolic alterations due to Coenzyme Q depletion in MCF-7 cells. Method: The Coenzyme Q depletion was induced by competitively inhibiting with 4-nitrobenzoate the coq2 enzyme, which catalyzes one of the final reactions in the biosynthetic pathway of CoQ. The bioenergetic and metabolic characteristics of control and coenzyme Q depleted cells were investigated using polarographic and spectroscopic assays. The effect of CoQ depletion on cell growth was analyzed in different metabolic conditions. Results: we showed that cancer cells could cope from energetic and oxidative stress due to mitochondrial dysfunction by reshaping their metabolism. In CoQ depleted cells, the glycolysis was upregulated together with increased glucose consumption, overexpression of GLUT1 and GLUT3, as well as activation of pyruvate kinase (PK). Moreover, the lactate secretion rate was reduced, suggesting that the pyruvate flux was redirected, toward anabolic pathways. Finally, we found a different expression pattern in enzymes involved in glutamine metabolism, and TCA cycle in CoQ depleted cells in comparison to controls. Conclusion: This work elucidated the metabolic alterations in CoQ-depleted cells and provided an insightful understanding of cancer metabolism targeting.

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Taguchi, Hideki. « Behavior of Co4+ ion in K2NiF4-type (Ca1+xSm1−x)CoO4 ». Solid State Sciences 9, n^o 9 (septembre 2007) : 869–73. http://dx.doi.org/10.1016/j.solidstatesciences.2007.01.009.

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Lee, Szu-Hsien, et Hsiu-Chuan Yen. « Comparison on the Roles of COQ3 and COQ7 Proteins in Maintaining Coenzyme Q 10 Levels, the Stability of Other COQ Proteins, and Mitochondrial Functions in Human Cells ». Free Radical Biology and Medicine 112 (novembre 2017) : 169–70. http://dx.doi.org/10.1016/j.freeradbiomed.2017.10.264.

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Yu, Yanan, Zhao Wang, Ziping Li, Xinxin Hang et Yanfeng Bi. « Assembly of {Co14} nanoclusters from adenine-modified Co4-thiacalix[4]arene units ». CrystEngComm 23, n^o 24 (2021) : 4382–88. http://dx.doi.org/10.1039/d1ce00440a.

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Mano, T., R. Sinohara, Y. Sawai, N. Oda, Y. Nishida, T. Mokuno, M. Kotake et al. « Effects of thyroid hormone on coenzyme Q and other free radical scavengers in rat heart muscle ». Journal of Endocrinology 145, n^o 1 (avril 1995) : 131–36. http://dx.doi.org/10.1677/joe.0.1450131.

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Abstract Active oxygen species are reported to cause organ damage. This study was therefore designed to determine the behaviour of antioxidants and free radical scavengers so as to reveal changes in animals in the hyper- and hypothyroid state. Levels of antioxidant factors (i.e. coenzyme Q (CoQ)10, CoQ9 and vitamin E) and free radical scavengers (catalase, glutathione peroxidase (GSH-PX) and superoxide dismutase (SOD)) were measured in the heart muscles of rats rendered hyper- or hypothyroid by 4 weeks of thyroxine (T4) or methimazol treatment. Serum levels of CoQ9 and total SOD were also measured. A significant reduction in CoQ9 levels was observed in the heart muscles of both hyper- and hypothyroid rats when compared with control hearts. There was no difference in serum CoQ9 levels in thyroid dysfunction when compared with control animals. Levels of vitamin E in the heart muscles of hyperthyroid rats were significantly increased, and there was no reduction in vitamin E levels in hypothyroid rats when compared with control hearts. GSH-PX levels in the heart muscle were reduced in hyperthyroid rats and increased in hypothyroid rats when compared with control hearts. However, there were no differences in catalase levels in heart muscle between hyper- and hypothyroid rats. The concentration of SOD in heart muscle was increased in hyperthyroid rats and was not decreased in hypothyroid rats compared with control rats, suggesting the induction of SOD by excessive production of O2−. These data suggest that the changes in these scavengers have some role in cardiac dysfunction in the hyper- and hypothyroid state in the rat. Journal of Endocrinology (1995) 145, 131–136

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Lu, Mei, Yulin Zhou, Zengge Wang, Zhongmin Xia, Jun Ren et Qiwei Guo. « Clinical phenotype, in silico and biomedical analyses, and intervention for an East Asian population-specific c.370G>A (p.G124S) COQ4 mutation in a Chinese family with CoQ10 deficiency-associated Leigh syndrome ». Journal of Human Genetics 64, n^o 4 (18 janvier 2019) : 297–304. http://dx.doi.org/10.1038/s10038-019-0563-y.

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De REVIERS, M. « Photopériodisme, développement testiculaire et production de spermatozoïdes chez les oiseaux domestiques ». INRAE Productions Animales 9, n^o 1 (17 février 1996) : 35–44. http://dx.doi.org/10.20870/productions-animales.1996.9.1.4033.

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La reproduction du Coq peut être dans une large mesure contrôlée par la durée quotidienne d’éclairement. Ce sont les variations de cette durée qui permettent le mieux de maîtriser la précocité de la production de spermatozoïdes, tandis que la persistance de cette production peut, sauf cas particulier, être la plus satisfaisante en jours courts. Cette condition est donc contradictoire à la fois avec une production de spermatozoïdes précoce, qui nécessite des jours croissants, et avec le maintien d’une intensité de ponte élevée, car on ne sait l’obtenir qu’en jours longs. Comme palliatif, on utilise donc dans la pratique un large effectif de coqs dont l’alimentation est par ailleurs rationnée afin de maintenir leur libido. L’insémination artificielle serait sans doute plus satisfaisante, en permettant d’adopter des conditions d’élevage spécifiques des coqs tout en réduisant leur nombre au minimum. Largement employée dans les autres espèces avicoles, son utilisation pour produire des poussins de chair bute encore sur des habitudes, sur la nécessité d’employer plus de personnel, plus qualifié et plus motivé, et sur une structure de filière où l’éleveur est encore parfois client de l’accouveur.

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Lohman, D. C., F. Forouhar, E. T. Beebe, M. S. Stefely, C. E. Minogue, A. Ulbrich, J. A. Stefely et al. « Mitochondrial COQ9 is a lipid-binding protein that associates with COQ7 to enable coenzyme Q biosynthesis ». Proceedings of the National Academy of Sciences 111, n^o 44 (22 octobre 2014) : E4697—E4705. http://dx.doi.org/10.1073/pnas.1413128111.

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He, Cuiwen H., Letian X. Xie, Christopher M. Allan, UyenPhuong C. Tran et Catherine F. Clarke. « Coenzyme Q supplementation or over-expression of the yeast Coq8 putative kinase stabilizes multi-subunit Coq polypeptide complexes in yeast coq null mutants ». Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids 1841, n^o 4 (avril 2014) : 630–44. http://dx.doi.org/10.1016/j.bbalip.2013.12.017.

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He, Cuiwen, Letian Xie, Christophe Allan, UyenPhuong Tran et Catherine Clarke. « Coenzyme Q supplementation or Over-Expression of the Yeast Coq8 Putative Kinase Stabilizes Multi-Subunit Coq Polypeptide Complexes in Yeast Coq Null Mutants ». Free Radical Biology and Medicine 65 (novembre 2013) : S125. http://dx.doi.org/10.1016/j.freeradbiomed.2013.10.705.

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Aydin, Deniz, Danielle C. Lohman, David J. Pagliarini et Matteo Dal Peraro. « A Combined Computational and Experimental Study to Investigate the Role of COQ9 in Promoting COQ Biosynthesis ». Biophysical Journal 114, n^o 3 (février 2018) : 460a. http://dx.doi.org/10.1016/j.bpj.2017.11.2541.

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Gigante, M., S. Diella, L. Santangelo, E. Trevisson, M. J. Acosta, M. Amatruda, G. Finzi et al. « Further phenotypic heterogeneity of CoQ10 deficiency associated with steroid resistant nephrotic syndrome and novel COQ2 and COQ6 variants ». Clinical Genetics 92, n^o 2 (22 mars 2017) : 224–26. http://dx.doi.org/10.1111/cge.12960.

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Porplycia, Danielle, Gigi Y. Lau, Jared McDonald, Zhilin Chen, Jeffrey G. Richards et Christopher D. Moyes. « Subfunctionalization of COX4 paralogs in fish ». American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 312, n^o 5 (1 mai 2017) : R671—R680. http://dx.doi.org/10.1152/ajpregu.00479.2016.

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Cytochrome c oxidase (COX) subunit 4 has two paralogs in most vertebrates. The mammalian COX4-2 gene is hypoxia responsive, and the protein has a disrupted ATP-binding site that confers kinetic properties on COX that distinguish it from COX4-1. The structure-function of COX4-2 orthologs in other vertebrates remains uncertain. Phylogenetic analyses suggest the two paralogs arose in basal vertebrates, but COX4-2 orthologs diverged faster than COX4-1 orthologs. COX4-1/4-2 protein levels in tilapia tracked mRNA levels across tissues, and did not change in hypoxia, arguing against a role for differential post-translational regulation of paralogs. The heart, and to a lesser extent the brain, showed a size-dependent shift from COX4-1 to COX4-2 (transcript and protein). ATP allosterically inhibited both velocity and affinity for oxygen in COX assayed from both muscle (predominantly COX4-2) and gill (predominantly COX4-1). We saw some evidence of cellular and subcellular discrimination of COX4 paralogs in heart. In cardiac ventricle, some non-cardiomyocyte cells were COX positive but lacked detectible COX4-2. Within heart, the two proteins partitioned to different mitochondrial subpopulations. Cardiac subsarcolemmal mitochondria had mostly COX4-1 and intermyofibrillar mitochondria had mostly COX4-2. Collectively, these data argue that, despite common evolutionary origins, COX4-2 orthologs of fish show unique patterns of subfunctionalization with respect to transcriptional and posttranslation regulation relative to the rodents and primates that have been studied to date.

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