Complexities of complex II: Sulfide metabolism in vivo |
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Authors: | Gary Cecchini |
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Affiliation: | 1.Molecular Biology Division, San Francisco VA Health Care System, San Francisco, California, USA;2.Department of Biochemistry & Biophysics, University of California, San Francisco, California, USA |
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Abstract: | High levels of H2S produced by gut microbiota can block oxygen utilization by inhibiting mitochondrial complex IV. Kumar et al. have shown how cells respond to this inhibition by using the mitochondrial sulfide oxidation pathway and reverse electron transport. The reverse activity of mitochondrial complex II (succinate-quinone oxidoreductase, i.e., fumarate reduction) generates oxidized coenzyme Q, which is then reduced by the mitochondrial sulfide quinone oxidoreductase to oxidize H2S. This newly identified redox circuitry points to the importance of complex II reversal in mitochondria during periods of hypoxia and cellular stress. |
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Keywords: | complex II succinate dehydrogenase sulfide quinone oxidoreductase fumarate reductase hydrogen sulfide electron transport coenzyme Q hypoxia mitochondria |
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