title: Coenzyme Q biosynthesis and its role in the respiratory chain structure.
abstract: Coenzyme Q (CoQ) is a unique electron carrier in the mitochondrial respiratory chain, which is synthesized on-site by a nuclear encoded multiprotein complex. CoQ receives electrons from different redox pathways, mainly NADH and FADH2 from tricarboxylic acid pathway, dihydroorotate dehydrogenase, electron transfer flavoprotein dehydrogenase and glycerol-3-phosphate dehydrogenase that support key aspects of the metabolism. Here we explore some lines of evidence supporting the idea of the interaction of CoQ with the respiratory chain complexes, contributing to their superassembly, including respirasome, and its role in reactive oxygen species production in the mitochondrial inner membrane. We also review the current knowledge about the involvement of mitochondrial genome defects and electron transfer flavoprotein dehydrogenase mutations in the induction of secondary CoQ deficiency. This mechanism would imply specific interactions coupling CoQ itself or the CoQ-biosynthetic apparatus with the respiratory chain components. These interactions would regulate mitochondrial CoQ steady-state levels and function. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
authors.affiliation: Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla 41013, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Alcázar-Fabra
authors.affiliation: Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla 41013, Spain. Electronic address: pnavas@upo.es.
authors.forename: Plácido
authors.initials: P
authors.lastname: Navas
authors.affiliation: Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla 41013, Spain.
authors.forename: Gloria
authors.initials: G
authors.lastname: Brea-Calvo
mesh_terms: D002952:Citric Acid Cycle / Q000235:genetics; D000090722:Dihydroorotate Dehydrogenase; D004579:Electron Transport; D045222:Electron Transport Chain Complex Proteins / Q000235:genetics / Q000378:metabolism*; D044927:Electron-Transferring Flavoproteins / Q000235:genetics / Q000378:metabolism; D004583:Electrons; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D014451:Ubiquinone / Q000096:biosynthesis*
chemical_list: D000090722:Dihydroorotate Dehydrogenase; D045222:Electron Transport Chain Complex Proteins; D044927:Electron-Transferring Flavoproteins; D009243:NAD; D014451:Ubiquinone; D010088:Oxidoreductases; D005993:Glycerolphosphate Dehydrogenase; D044925:Oxidoreductases Acting on CH-CH Group Donors
keywords: Coenzyme Q; Coenzyme Q deficiency; Mitochondria; ROS; Respiratory complexes