Cyclophilin D Modulates Mitochondrial F0F1-ATP Synthase by Interacting with the Lateral Stalk of the Complex

Abstract

Blue native gel electrophoresis purification and immunoprecipitation of F 0 F 1 -ATP synthase from bovine heart mitochondria revealed that cyclophilin (CyP) D associates to the complex. Treatment of intact mitochondria with the membrane-permeable bifunctional reagent dimethyl 3,3-dithiobis-propionimidate (DTBP) cross-linked CyPD with the lateral stalk of ATP synthase, whereas no interactions with F 1 sector subunits, the ATP synthase natural inhibitor protein IF1, and the ATP/ADP carrier were observed. The ATP synthase-CyPD interactions have functional consequences on enzyme catalysis and are modulated by phosphate (increased CyPD binding and decreased enzyme activity) and cyclosporin (Cs) A (decreased CyPD binding and increased enzyme activity). Treatment of MgATP submitochondrial particles or intact mitochondria with CsA displaced CyPD from membranes and activated both hydrolysis and synthesis of ATP sustained by the enzyme. No effect of CsA was detected in CyPD-null mitochondria, which displayed a higher specific activity of the ATP synthase than wild-type mitochondria. Modulation by CyPD binding appears to be independent of IF1, whose association to ATP synthase was not affected by CsA treatment. These findings demonstrate that CyPD association to the lateral stalk of ATP synthase modulates the activity of the complex.

Evaluation of intramitochondrial ATP levels identifies G0/G1 switch gene 2 as a positive regulator of oxidative phosphorylation

“…Combined with the findings from this study, we hypothesize that G0s2 may lower the activation barrier of the F o F 1 -ATP synthase nanomotor and enhance the ATP production rate with the equivalent proton motive driving force (PMF; i.e., the sum of the membrane potential and the pH gradient). Activation barriers might be generated by various factors, such as friction between the stator and rotor of F o F 1 -ATP synthase, physical and electrical resistance to proton transport through the channel, and the existence of rotary blockers such as the bacterial e-subunit and cyclophilin D (31). The increased ATP production rate caused by G0s2 overexpression observed in the MASC assay supports this hypothesis, because the PMF in the initial phase of this assay should be the same.…”

Role of the c subunit of the FOATP synthase in mitochondrial permeability transition

“…31 In addition, CYPD as well as two distinct anti-apoptotic members of the BCL-2 family, namely BCL-X L and MCL-1, have recently been reported to regulate mitochondrial ATP synthesis by physically interacting with the F 1 F O ATP synthase. [32][33][34][35] Driven by these observations and by the facts that: (1) a selective inhibitor of the F O subunit of ATP synthase, i.e., oligomycin, is able to prevent cell death as induced by tumor necrosis factor α (TNFα), 36 the multi-kinase inhibitor staurosporine 37 or BAX overexpression; 38 and that (2) the activity of both the PTPC and F 1 F O ATP synthase is modulated by Mg 2+ ions; 39,40 we decided to investigate the role of F O ATP synthase subunits in MPT.…”

The Mitochondrial Complex V–Associated Large-Conductance Inner Membrane Current Is Regulated by Cyclosporine and Dexpramipexole

“…We determined that components of the F 1 including the b-subunit prevent pore opening by positioning themselves over the pore of a leak conductance within the c-subunit ring Chen et al, 2011). Our model predicts that cyclophilin D, which is known to bind to OSCP (Giorgio et al, 2009), acts on the pore by facilitating the removal of the F 1 from the c-subunit in a CsA-sensitive manner during pore opening . Because DEX binds in a similar configuration to that of CsA, we suggest here that it acts similarly to CsA, although how the exact binding domains within F 1 differ is as yet undetermined.…”

“…Recently we presented evidence that cyclosporine A (CsA), a compound that is a known modulator of mitochondrial function (Szabo and Zoratti, 1991;Giorgio et al, 2009), and dexpramipexole (DEX) (Gribkoff and Bozik, 2008) inhibited stress-and injury-induced large-conductance currents recorded from whole neuronal mitochondria . DEX is the nondopaminergic R(1) enantiomer of the high-affinity dopamine agonist and Parkinson's disease therapeutic pramipexole (Mirapex; Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT) (Gribkoff and Bozik, 2008).…”