Control of mitochondrial superoxide production by reverse electron transport at complex I.
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Authors
Robb, Ellen L
Hall, Andrew R
Prime, Tracy A
Eaton, Simon
Szibor, Marten
James, Andrew
Publication Date
2018-06-22Journal Title
J Biol Chem
ISSN
0021-9258
Publisher
Elsevier BV
Volume
293
Issue
25
Pages
9869-9879
Language
eng
Type
Article
This Version
VoR
Physical Medium
Print-Electronic
Metadata
Show full item recordCitation
Robb, E. L., Hall, A. R., Prime, T. A., Eaton, S., Szibor, M., Viscomi, C., James, A., & et al. (2018). Control of mitochondrial superoxide production by reverse electron transport at complex I.. J Biol Chem, 293 (25), 9869-9879. https://doi.org/10.1074/jbc.RA118.003647
Abstract
The generation of mitochondrial superoxide (O2̇̄) by reverse electron transport (RET) at complex I causes oxidative damage in pathologies such as ischemia reperfusion injury, but also provides the precursor to H2O2 production in physiological mitochondrial redox signaling. Here, we quantified the factors that determine mitochondrial O2̇̄ production by RET in isolated heart mitochondria. Measuring mitochondrial H2O2 production at a range of proton-motive force (Δp) values and for several coenzyme Q (CoQ) and NADH pool redox states obtained with the uncoupler p-trifluoromethoxyphenylhydrazone, we show that O2̇̄ production by RET responds to changes in O2 concentration, the magnitude of Δp, and the redox states of the CoQ and NADH pools. Moreover, we determined how expressing the alternative oxidase from the tunicate Ciona intestinalis to oxidize the CoQ pool affected RET-mediated O2̇̄ production at complex I, underscoring the importance of the CoQ pool for mitochondrial O2̇̄ production by RET. An analysis of O2̇̄ production at complex I as a function of the thermodynamic forces driving RET at complex I revealed that many molecules that affect mitochondrial reactive oxygen species production do so by altering the overall thermodynamic driving forces of RET, rather than by directly acting on complex I. These findings clarify the factors controlling RET-mediated mitochondrial O2̇̄ production in both pathological and physiological conditions. We conclude that O2̇̄ production by RET is highly responsive to small changes in Δp and the CoQ redox state, indicating that complex I RET represents a major mode of mitochondrial redox signaling.
Keywords
Mitochondria, Heart, Animals, Mice, Inbred C57BL, Mice, Rats, Rats, Wistar, Hydrogen Peroxide, Superoxides, Ubiquinone, Electron Transport Complex I, Signal Transduction, Electron Transport, Oxidative Phosphorylation, Female, Male
Sponsorship
Medical Research Council (MC_UU_00015/3)
Wellcome Trust (110159/Z/15/Z)
Medical Research Council (MC_UP_1002/1)
MRC (MC_UP_1002/1)
Medical Research Council (MC_U105663142)
Medical Research Council (MC_UU_00015/8)
MRC (MC_UU_00015/8)
Identifiers
External DOI: https://doi.org/10.1074/jbc.RA118.003647
This record's URL: https://www.repository.cam.ac.uk/handle/1810/287131
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