Lateral pH gradient between OXPHOS complex IV and FoF1 ATP-synthase in folded mitochondrial membranes

Rieger, Bettina; Junge, Wolfgang; Busch, Karin B.

doi:10.1016/j.bbabio.2014.05.307

Cited by 27 publications

(55 citation statements)

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“…perturbing a small region of the organelle-for example, acquisition of a single frame expended 5-10 s (Amchenkova et al, 1988;Skulachev, 2001). Indeed, our study can provide an explanation for heterogeneous distribution of protons along the cristae membrane and between the cristae and the IMS Rieger et al, 2014;Pham et al, 2016). Our study suggests that, unless imaging at ≥ 1 frame(s) per second, observing partial depolarization events is improbable.…”

Section: Of 21mentioning

confidence: 73%

Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

et al. 2019

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The mitochondrial membrane potential (ΔΨm) is the main driver of oxidative phosphorylation (OXPHOS). The inner mitochondrial membrane (IMM), consisting of cristae and inner boundary membranes (IBM), is considered to carry a uniform ΔΨm. However, sequestration of OXPHOS components in cristae membranes necessitates a re‐examination of the equipotential representation of the IMM. We developed an approach to monitor ΔΨm at the resolution of individual cristae. We found that the IMM was divided into segments with distinct ΔΨm, corresponding to cristae and IBM. ΔΨm was higher at cristae compared to IBM. Treatment with oligomycin increased, whereas FCCP decreased, ΔΨm heterogeneity along the IMM. Impairment of cristae structure through deletion of MICOS‐complex components or Opa1 diminished this intramitochondrial heterogeneity of ΔΨm. Lastly, we determined that different cristae within the individual mitochondrion can have disparate membrane potentials and that interventions causing acute depolarization may affect some cristae while sparing others. Altogether, our data support a new model in which cristae within the same mitochondrion behave as independent bioenergetic units, preventing the failure of specific cristae from spreading dysfunction to the rest.

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Section: Of 21mentioning

confidence: 73%

Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

et al. 2019

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“…Therefore, a salt solution (125 mmol/L KCl, 20 mmol/L NaCl, 0.5 mmol/L CaCl 2 , and 0.5 mmol/L MgSO 4 ) was supplemented with MES (20 mmol/L, pH 6.5), BES (20 mmol/L, pH 7.0), or HEPPSO buffer (25 mmol/L, pH 7.5 and 8.0) adjusted to the desired pH by 1 mol/L HCl or NaOH. Cellular equilibration was achieved by addition of FCCP (10 µmol/L), nigericin (1 µmol/L), and oligomycin (5 µg/mL) as previously reported for calibration of superecliptic pHluorin …”

Section: Methodsmentioning

confidence: 99%

“…Cellular equilibration was achieved by addition of FCCP (10 µmol/L), nigericin (1 µmol/L), and oligomycin (5 µg/mL) as previously reported for calibration of superecliptic pHluorin. 50…”

Section: Calibration Of Hyper-3 For Different Ph Valuesmentioning

confidence: 99%

Pseudomonas Quinolone Signal molecule PQS behaves like a B Class inhibitor at the I _Q site of mitochondrial complex I

Rieger

Thierbach²,

Ommer-Bläsius

et al. 2020

FASEB BioAdvances

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Pseudomonas aeruginosa is a Gram‐negative bacterium of the proteobacteria class, and one of the most common causes of nosocomial infections. For example, it causes chronic pneumonia in cystic fibrosis patients. Patient sputum contains 2‐heptyl‐4‐hydroxyquinoline N‐oxide [HQNO] and Pseudomonas quorum sensing molecules such as the Pseudomonas quinolone signal [PQS]. It is known that HQNO inhibits the enzyme activity of mitochondrial and bacterial complex III at the Qi (quinone reduction) site, but the target of PQS is not known. In this work we have shown that PQS has a negative effect on mitochondrial respiration in HeLa and A549 cells. It specifically inhibits the complex I of the respiratory chain. In vitro analyses showed a partially competitive inhibition with respect to ubiquinone at the IQ site. In competing studies with Rotenone, PQS suppressed the ROS‐promoting effect of Rotenone, which is typical for a B‐type inhibitor. Prolonged incubation with PQS also had an effect on the activity of complex III.

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“…ATP synthase forms dimers and oligomers (Wittig & Schägger, ; Habersetzer et al ., ) and dimeric (or oligomeric) ATP synthase appears to be involved in the formation of cristae of the inner mitochondrial membrane (Paumard et al ., ), which constitute a localized microenvironment with a high capacity to maintain the PMF. Protons pumped by respiratory complexes could diffuse laterally (Zhang et al ., ; Rieger, Junge & Busch, ) along the membrane surface to the F O c‐ring of the ATP synthase. This proton diffusion could involve water molecules bound at the surface of the membrane (Brändén et al ., ; Zhang et al ., ) or head‐groups of cardiolipin (Haines & Dencher, ; but see Springer et al ., ), which is associated with the OXPHOS complexes and is essential for their supramolecular organization (Paradies et al ., ).…”

Section: Protonmotive Coupling In Mitochondrial Oxphosmentioning

confidence: 99%

The mechanism of coupling between oxido‐reduction and proton translocation in respiratory chain enzymes

2017

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The respiratory chain of mitochondria and bacteria is made up of a set of membrane-associated enzyme complexes which catalyse sequential, stepwise transfer of reducing equivalents from substrates to oxygen and convert redox energy into a transmembrane protonmotive force (PMF) by proton translocation from a negative (N) to a positive (P) aqueous phase separated by the coupling membrane. There are three basic mechanisms by which a membrane-associated redox enzyme can generate a PMF. These are membrane anisotropic arrangement of the primary redox catalysis with: (i) vectorial electron transfer by redox metal centres from the P to the N side of the membrane; (ii) hydrogen transfer by movement of quinones across the membrane, from a reduction site at the N side to an oxidation site at the P side; (iii) a different type of mechanism based on co-operative allosteric linkage between electron transfer at the metal redox centres and transmembrane electrogenic proton translocation by apoproteins.The results of advanced experimental and theoretical analyses and in particular X-ray crystallography show that these three mechanisms contribute differently to the protonmotive activity of cytochrome c oxidase, ubiquinone-cytochrome c oxidoreductase and NADH-ubiquinone oxidoreductase of the respiratory chain.This review considers the main features, recent experimental advances and still unresolved problems in the molecular/atomic mechanism of coupling between the transfer of reducing equivalents and proton translocation in these three protonmotive redox complexes.

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Lateral pH gradient between OXPHOS complex IV and FoF1 ATP-synthase in folded mitochondrial membranes

Cited by 27 publications

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Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

Pseudomonas Quinolone Signal molecule PQS behaves like a B Class inhibitor at the I _Q site of mitochondrial complex I

The mechanism of coupling between oxido‐reduction and proton translocation in respiratory chain enzymes

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Lateral pH gradient between OXPHOS complex IV and FoF1 ATP-synthase in folded mitochondrial membranes

Cited by 27 publications

References 0 publications

Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

Individual cristae within the same mitochondrion display different membrane potentials and are functionally independent

Pseudomonas Quinolone Signal molecule PQS behaves like a B Class inhibitor at the I Q site of mitochondrial complex I

The mechanism of coupling between oxido‐reduction and proton translocation in respiratory chain enzymes

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Product

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Pseudomonas Quinolone Signal molecule PQS behaves like a B Class inhibitor at the I _Q site of mitochondrial complex I