Inhibitors of ROS production by the ubiquinone-binding site of mitochondrial complex I identified by chemical screening

Neurons depend on oxidative phosphorylation for energy generation, whereas astrocytes do not, a distinctive feature that is essential for neurotransmission and neuronal survival. However, any link between these metabolic differences and the structural organization of the mitochondrial respiratory chain is unknown. Here, we investigated this issue and found that, in neurons, mitochondrial complex I is predominantly assembled into supercomplexes, whereas in astrocytes the abundance of free complex I is higher. The presence of free complex I in astrocytes correlates with the severalfold higher reactive oxygen species (ROS) production by astrocytes compared with neurons. Using a complexomics approach, we found that the complex I subunit NDUFS1 was more abundant in neurons than in astrocytes. Interestingly, NDUFS1 knockdown in neurons decreased the association of complex I into supercomplexes, leading to impaired oxygen consumption and increased mitochondrial ROS. Conversely, overexpression of NDUFS1 in astrocytes promoted complex I incorporation into supercomplexes, decreasing ROS. Thus, complex I assembly into supercomplexes regulates ROS production and may contribute to the bioenergetic differences between neurons and astrocytes.

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Superoxide formation at the Q‐binding site of mitochondrial complex I does not arise from a semiquinone that has direct access to the bulk membrane QH 2 /Q pool

The FASEB Journal ◽

10.1096/fasebj.24.1_supplement.lb148 ◽

2010 ◽

Vol 24 (S1) ◽

Author(s):

Jason R Treberg ◽

Casey L Quinlan ◽

Martin D Brand

Keyword(s):

Binding Site ◽

Complex I ◽

Direct Access ◽

Mitochondrial Complex I ◽

Mitochondrial Complex ◽

Superoxide Formation ◽

Bulk Membrane

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Cryo-EM structure of respiratory complex I at work

eLife ◽

10.7554/elife.39213 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 43

Author(s):

Kristian Parey ◽

Ulrich Brandt ◽

Hao Xie ◽

Deryck J Mills ◽

Karin Siegmund ◽

...

Keyword(s):

Complex I ◽

Atp Synthesis ◽

Proton Pumping ◽

Mitochondrial Complex I ◽

Mitochondrial Complex ◽

Membrane Protein Complex ◽

Change Mechanism ◽

Steady State Activity ◽

Respiratory Complex I ◽

Ubiquinone Binding

Mitochondrial complex I has a key role in cellular energy metabolism, generating a major portion of the proton motive force that drives aerobic ATP synthesis. The hydrophilic arm of the L-shaped ~1 MDa membrane protein complex transfers electrons from NADH to ubiquinone, providing the energy to drive proton pumping at distant sites in the membrane arm. The critical steps of energy conversion are associated with the redox chemistry of ubiquinone. We report the cryo-EM structure of complete mitochondrial complex I from the aerobic yeast Yarrowia lipolytica both in the deactive form and after capturing the enzyme during steady-state activity. The site of ubiquinone binding observed during turnover supports a two-state stabilization change mechanism for complex I.

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Changes in mitochondrial complex I activity and coenzyme Q binding site in Leber's hereditary optic neuropathy (LHON)

Molecular Aspects of Medicine ◽

10.1016/s0098-2997(97)00028-9 ◽

1997 ◽

Vol 18 ◽

pp. 263-267 ◽

Cited By ~ 12

Author(s):

A. Ghelli ◽

M. Degli Esposti ◽

V. Carelli ◽

G. Lenaz

Keyword(s):

Binding Site ◽

Optic Neuropathy ◽

Complex I ◽

Coenzyme Q ◽

Mitochondrial Complex I ◽

Leber’S Hereditary Optic Neuropathy ◽

Leber's Hereditary Optic Neuropathy ◽

Mitochondrial Complex ◽

Complex I Activity ◽

Hereditary Optic Neuropathy

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Physiologic Implications of Reactive Oxygen Species Production by Mitochondrial Complex I Reverse Electron Transport

Antioxidants ◽

10.3390/antiox8080285 ◽

2019 ◽

Vol 8 (8) ◽

pp. 285 ◽

Cited By ~ 11

Author(s):

John O. Onukwufor ◽

Brandon J. Berry ◽

Andrew P. Wojtovich

Keyword(s):

Reactive Oxygen Species ◽

Electron Transport ◽

Complex I ◽

Reactive Oxygen ◽

Reverse Direction ◽

Mitochondrial Complex I ◽

Ros Production ◽

Oxygen Species ◽

Mitochondrial Complex ◽

Reverse Electron Transport

Mitochondrial reactive oxygen species (ROS) can be either detrimental or beneficial depending on the amount, duration, and location of their production. Mitochondrial complex I is a component of the electron transport chain and transfers electrons from NADH to ubiquinone. Complex I is also a source of ROS production. Under certain thermodynamic conditions, electron transfer can reverse direction and reduce oxygen at complex I to generate ROS. Conditions that favor this reverse electron transport (RET) include highly reduced ubiquinone pools, high mitochondrial membrane potential, and accumulated metabolic substrates. Historically, complex I RET was associated with pathological conditions, causing oxidative stress. However, recent evidence suggests that ROS generation by complex I RET contributes to signaling events in cells and organisms. Collectively, these studies demonstrate that the impact of complex I RET, either beneficial or detrimental, can be determined by the timing and quantity of ROS production. In this article we review the role of site-specific ROS production at complex I in the contexts of pathology and physiologic signaling.

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Exploring the binding site of acetogenin in the ND1 subunit of bovine mitochondrial complex I

Biochimica et Biophysica Acta (BBA) - Bioenergetics ◽

10.1016/j.bbabio.2009.02.016 ◽

2009 ◽

Vol 1787 (9) ◽

pp. 1106-1111 ◽

Cited By ~ 30

Author(s):

Koji Sekiguchi ◽

Masatoshi Murai ◽

Hideto Miyoshi

Keyword(s):

Binding Site ◽

Complex I ◽

Mitochondrial Complex I ◽

Mitochondrial Complex

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Moderate Hydrogen Peroxide Postconditioning Ameliorates Ischemia/Reperfusion Injury in Cardiomyocytes via STAT3-Induced Calcium, ROS, and ATP Homeostasis

Pharmacology ◽

10.1159/000511961 ◽

2020 ◽

pp. 1-11

Author(s):

Lan Wu ◽

Wen-qing Huang ◽

Cheng-chao Yu ◽

Yan-fei Li

Keyword(s):

Complex I ◽

Ischemia Reperfusion ◽

Calcium Overload ◽

Mitochondrial Calcium ◽

Mitochondrial Complex I ◽

Ros Production ◽

Mitochondrial Complex ◽

Rat Cardiomyocytes ◽

Early Reperfusion ◽

Gene And Protein Expression

Introduction: Moderate hydrogen peroxide postconditioning (H2O2PoC) activates signal transducer and activator of transcription 3 (STAT3) to alleviate mitochondrial calcium overload during cardiac ischemia/reperfusion (I/R). However, the initial time window of STAT3-induced calcium hemostasis, the production of reactive oxygen species (ROS) and adenosine triphosphate (ATP) in H2O2PoC, and its regulated mechanism remain unknown. This study aimed to investigate H2O2PoC-induced homeostasis of calcium, ROS and ATP, and the role of STAT3 in the regulation. Methods: Isolated rat cardiomyocytes were exposed to H2O2PoC and Janus kinase 2 (JAK2)/STAT3 inhibitor AG490 during I/R. Ca2+ transients, cell contraction, intracellular calcium concentration, ROS production, ATP contents, phosphorylation of STAT3, gene and protein expression of manganese superoxide dismutase (MnSOD), metallothionein 1 (MT1) and metallothionein 2 (MT2), as well as activities of mitochondrial complex I and complex II were detected. Results: Moderate H2O2PoC improved post-ischemic Ca2+ transients and cell contraction recovery as well as alleviated cytosolic and mitochondrial calcium overload, which were abrogated by AG490 in rat cardiomyocytes. Moderate H2O2PoC increased ROS production and rate of ROS production at early reperfusion in rat I/R cardiomyocytes, and this phenomenon was also abrogated by AG490. Notably, the expression of phosphorylated nuclear STAT3; gene and protein expression of MnSOD, MT1, and MT2; and activities of mitochondrial complex I and complex II were upregulated by moderate H2O2PoC but downregulated by AG490. Conclusion: These findings indicated that the cardioprotection of moderate H2O2PoC against cardiac I/R could be associated with activated STAT3 at early reperfusion to maintain calcium, ROS, and ATP homeostasis in rat cardiomyocytes.

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