Complex II ambiguities

high-resolution terminology - matching measurements at high-resolution

Complex II ambiguities

Description

The current narrative that the reduced coenzymes NADH and FADH2 feed electrons from the tricarboxylic acid (TCA) cycle into the mitochondrial electron transfer system can create ambiguities around respiratory Complex CII. Succinate dehydrogenase or CII reduces FAD to FADH2 in the canonical forward TCA cycle. However, some graphical representations of the membrane-bound electron transfer system (ETS) depict CII as the site of oxidation of FADH2. This leads to the false believe that FADH2 generated by electron transferring flavoprotein (CETF) in fatty acid oxidation and mitochondrial glycerophosphate dehydrogenase (CGpDH) feeds electrons into the ETS through CII. In reality, NADH and succinate produced in the TCA cycle are the substrates of Complexes CI and CII, respectively, and the reduced flavin groups FMNH2 and FADH2 are downstream products of CI and CII, respectively, carrying electrons from CI and CII into the Q-junction. Similarly, CETF and CGpDH feed electrons into the Q-junction but not through CII. The ambiguities surrounding Complex II in the literature call for quality control, to secure scientific standards in current communications on bioenergetics and support adequate clinical applications.

Abbreviation: CII ambiguities

Reference: Gnaiger E (2023) Complex II ambiguities ― FADH₂ in the electron transfer system. MitoFit Preprints 2023.3.v6. https://doi.org/10.26124/mitofit:2023-0003

A game of cards

33 copies or variations of a CII ambiguity theme

## Gopalakrishnan S, Mehrvar S, Maleki S, Schmitt H, Summerfelt P, Dubis AM, Abroe B, Connor TB Jr, Carroll J, Huddleston W, Ranji M, Eells JT (2020) Photobiomodulation preserves mitochondrial redox state and is retinoprotective in a rodent model of retinitis pigmentosa. Sci Rep 10:20382. - »Bioblast link«

S4

## Anoar S, Woodling NS, Niccoli T (2021) Mitochondria dysfunction in frontotemporal dementia/amyotrophic lateral sclerosis: lessons from Drosophila models. Front Neurosci 15:786076. - »Bioblast link«

S4

## Chakrabarty RP, Chandel NS (2021) Mitochondria as signaling organelles control mammalian stem cell fate. Cell Stem Cell 28:394-408. - »Bioblast link«

S2

## Han S, Chandel NS (2021) Lessons from cancer metabolism for pulmonary arterial hypertension and fibrosis. Am J Respir Cell Mol Biol 65:134-45. - »Bioblast link«

S1

## Ignatieva E, Smolina N, Kostareva A, Dmitrieva R (2021) Skeletal muscle mitochondria dysfunction in genetic neuromuscular disorders with cardiac phenotype. Int J Mol Sci 22:7349. - »Bioblast link«

S4

## Nguyen TT, Nguyen DK, Ou YY (2021) Addressing data imbalance problems in ligand-binding site prediction using a variational autoencoder and a convolutional neural network. Brief Bioinform 22:bbab277. - »Bioblast link«

S4

## Prasuhn J, Davis RL, Kumar KR (2021) Targeting mitochondrial impairment in Parkinson's disease: challenges and opportunities. Front Cell Dev Biol 8:615461. - »Bioblast link«

S4

## Shields HJ, Traa A, Van Raamsdonk JM (2021) Beneficial and detrimental effects of reactive oxygen species on lifespan: a comprehensive review of comparative and experimental studies. Front Cell Dev Biol 9:628157. - »Bioblast link«

S4

## Turton N, Bowers N, Khajeh S, Hargreaves IP, Heaton RA (2021) Coenzyme Q10 and the exclusive club of diseases that show a limited response to treatment. Expert Opinion Orphan Drugs 9:151-60. - »Bioblast link«

S4

## Vargas-Mendoza N, Angeles-Valencia M, Morales-González Á, Madrigal-Santillán EO, Morales-Martínez M, Madrigal-Bujaidar E, Álvarez-González I, Gutiérrez-Salinas J, Esquivel-Chirino C, Chamorro-Cevallos G, Cristóbal-Luna JM, Morales-González JA (2021) Oxidative stress, mitochondrial function and adaptation to exercise: new perspectives in nutrition. Life (Basel) 11:1269. - »Bioblast link«

S4

## Vesga LC, Silva AMP, Bernal CC, Mendez-Sánchez SC, Bohórquez ARR (2021) Tetrahydroquinoline/4,5-dihydroisoxazole hybrids with a remarkable effect over mitochondrial bioenergetic metabolism on melanoma cell line B16F10. Med Chem Res 30:2127–43. - »Bioblast link«

S4

## Yin M, O'Neill LAJ (2021) The role of the electron transport chain in immunity. FASEB J 35:e21974. - »Bioblast link«

S4

## Aye ILMH, Aiken CE, Charnock-Jones DS, Smith GCS (2022) Placental energy metabolism in health and disease-significance of development and implications for preeclampsia. Am J Obstet Gynecol 226:S928-44. - »Bioblast link«

S1

## Fahimi P, Matta CF (2022) The hot mitochondrion paradox: reconciling theory and experiment. Trends in Chemistry 4:4-20. - »Bioblast link«

S4

## Foo J, Bellot G, Pervaiz S, Alonso S (2022) Mitochondria-mediated oxidative stress during viral infection. Trends Microbiol 30:679-92. - »Bioblast link«

S4

## Gallinat A, Vilahur G, Padró T, Badimon L (2022) Network-assisted systems biology analysis of the mitochondrial proteome in a pre-clinical model of ischemia, revascularization and post-conditioning. Int J Mol Sci 23:2087. - »Bioblast link«

S5.3

## Iakovou E, Kourti M (2022) A comprehensive overview of the complex role of oxidative stress in aging, the contributing environmental stressors and emerging antioxidant therapeutic interventions. Front Aging Neurosci 14:827900. - »Bioblast link«

S1

xx Jayasankar V, Vrdoljak N, Roma A, Ahmed N, Tcheng M, Minden MD, Spagnuolo PA (2022) Novel mango ginger bioactive (2,4,6-trihydroxy-3,5-diprenyldihydrochalcone) inhibits mitochondrial metabolism in combination with Avocatin B. ACS Omega 7:1682-93. - »Bioblast link«

S2

## Joshi A, Ito T, Picard D, Neckers L (2022) The mitochondrial HSP90 paralog TRAP1: structural dynamics, interactome, role in metabolic regulation, and inhibitors. Biomolecules 12:880. - »Bioblast link«

S4

## Manickam DS (2022) Delivery of mitochondria via extracellular vesicles - a new horizon in drug delivery. J Control Release 343:400-7. - »Bioblast link«

S4

## Narine M, Colognato H (2022) Current insights into oligodendrocyte metabolism and its power to sculpt the myelin landscape. Front Cell Neurosci 16:892968. - »Bioblast link«

S2

## Sainero-Alcolado L, Liaño-Pons J, Ruiz-Pérez MV, Arsenian-Henriksson M (2022) Targeting mitochondrial metabolism for precision medicine in cancer. Cell Death Differ 29:1304-17. - »Bioblast link«

S4

## Wu Z, Ho WS, Lu R (2022) Targeting mitochondrial oxidative phosphorylation in glioblastoma therapy. Neuromolecular Med 24:18-22. - »Bioblast link«

S4

## Yang Y, Zhang X, Hu X, Zhao J, Chen X, Wei X, Yu X (2022) Analysis of the differential metabolic pathway of cultured Chlorococcum humicola with hydroquinone toxic sludge extract. J Cleaner Production 370:133486. - »Bioblast link«

S4

## Yuan Q, Zeng ZL, Yang S, Li A, Zu X, Liu J (2022) Mitochondrial stress in metabolic inflammation: modest benefits and full losses. Oxid Med Cell Longev 2022:8803404. - »Bioblast link«

S2

## Cojocaru KA, Luchian I, Goriuc A, Antoci LM, Ciobanu CG, Popescu R, Vlad CE, Blaj M, Foia LG (2023) Mitochondrial dysfunction, oxidative stress, and therapeutic strategies in diabetes, obesity, and cardiovascular disease. Antioxidants (Basel) 12:658. - »Bioblast link«

S4

## Egan B, Sharples AP (2023) Molecular responses to acute exercise and their relevance for adaptations in skeletal muscle to exercise training. Physiol Rev 103:2057-2170. - »Bioblast link«

S4

## Faria R, Boisguérin P, Sousa Â, Costa D (2023) Delivery systems for mitochondrial gene therapy: a review. Pharmaceutics 15:572. - »Bioblast link«

S4

## George CE, Saunders CV, Morrison A, Scorer T, Jones S, Dempsey NC (2023) Cold stored platelets in the management of bleeding: is it about bioenergetics? Platelets 34:2188969 - »Bioblast link«

S4

## Keidar N, Peretz NK, Yaniv Y (2023) Ca²⁺ pushes and pulls energetics to maintain ATP balance in atrial cells: computational insights. Front Physiol 14:1231259. - »Bioblast link«

S5.3

## Lu F (2023) Hypothetical hydrogenase activity of human mitochondrial Complex I and its role in preventing cancer transformation. Explor Res Hypothesis Med 8:280-5. - »Bioblast link«

S4

## Martell E, Kuzmychova H, Kaul E, Senthil H, Chowdhury SR, Morrison LC, Fresnoza A, Zagozewski J, Venugopal C, Anderson CM, Singh SK, Banerji V, Werbowetski-Ogilvie TE, Sharif T (2023) Metabolism-based targeting of MYC via MPC-SOD2 axis-mediated oxidation promotes cellular differentiation in group 3 medulloblastoma. Nat Commun 14:2502. - »Bioblast link«

S4

## Solhaug A, Gjessing M, Sandvik M, Eriksen GS (2023) The gill epithelial cell lines RTgill-W1, from Rainbow trout and ASG-10, from Atlantic salmon, exert different toxicity profiles towards rotenone. Cytotechnology 75:63-75. - »Bioblast link«

S4

and more ..

MitoPedia concepts: MiP concept 

MitoPedia topics: Enzyme, Substrate and metabolite 

Labels:

MitoPedia:FAT4BRAIN