Natural tetramic acids elicit multiple inhibitory actions against mitochondrial machineries presiding over oxidative phosphorylation

2021 ◽  
Author(s):  
Yufu Unten ◽  
Masatoshi Murai ◽  
Katsuyuki Sakai ◽  
Yukihiro Asami ◽  
Takenori Yamamoto ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Atp Synthesis ◽  
Anion Channel ◽  
Complex Iii ◽  
Tetramic Acid ◽  
Voltage Dependent Anion Channel ◽  
Saccharomyces Cerevisiae Mitochondria ◽  
Tetramic Acids ◽  
Fof1 Atp Synthase

Abstract The mitochondrial machineries presiding over ATP synthesis via oxidative phosphorylation are promising druggable targets. Fusaramin, a 3-acyl tetramic acid isolated from Fusarium concentricum FKI-7550, is an inhibitor of oxidative phosphorylation in Saccharomyces cerevisiae mitochondria, although its target has yet to be identified. Fusaramin significantly interfered with [3H]ADP uptake by yeast mitochondria at the concentration range inhibiting oxidative phosphorylation. A photoreactive fusaramin derivative (pFS-5) specifically labeled voltage-dependent anion channel 1 (VDAC1), which facilitates trafficking of ADP/ATP across the outer mitochondrial membrane. These results strongly suggest that the inhibition of oxidative phosphorylation by fusaramin is predominantly attributable to the impairment of VDAC1 functions. Fusaramin also inhibited FoF1-ATP synthase and ubiquinol-cytochrome c oxidoreductase (complex III) at concentrations higher than those required for the VDAC inhibition. Considering that other tetramic acid derivatives are reported to inhibit FoF1-ATP synthase and complex III, natural tetramic acids were found to elicit multiple inhibitory actions against mitochondrial machineries.

scholarly journals Biochemical and Genetic Analysis of the Mitochondrial Response of Yeast to BAX and BCL-XL

2000 ◽  
Vol 20 (9) ◽  
pp. 3125-3136 ◽  
Author(s):  
Atan Gross ◽  
Kirsten Pilcher ◽  
Elizabeth Blachly-Dyson ◽  
Emy Basso ◽  
Jennifer Jockel ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Genome ◽  
Atp Synthase ◽  
Mitochondrial Permeability Transition ◽  
Family Members ◽  
Growth Arrest ◽  
Anion Channel ◽  
Cell Killing ◽  
Β Subunit ◽  
Voltage Dependent Anion Channel

ABSTRACT The BCL-2 family includes both proapoptotic (e.g., BAX and BAK) and antiapoptotic (e.g., BCL-2 and BCL-XL) molecules. The cell death-regulating activity of BCL-2 members appears to depend on their ability to modulate mitochondrial function, which may include regulation of the mitochondrial permeability transition pore (PTP). We examined the function of BAX and BCL-XL using genetic and biochemical approaches in budding yeast because studies with yeast suggest that BCL-2 family members act upon highly conserved mitochondrial components. In this study we found that in wild-type yeast, BAX induced hyperpolarization of mitochondria, production of reactive oxygen species, growth arrest, and cell death; however, cytochrome c was not released detectably despite the induction of mitochondrial dysfunction. Coexpression of BCL-XL prevented all BAX-mediated responses. We also assessed the function of BCL-XL and BAX in the same strain of Saccharomyces cerevisiae with deletions of selected mitochondrial proteins that have been implicated in the function of BCL-2 family members. BAX-induced growth arrest was independent of the tested mitochondrial components, including voltage-dependent anion channel (VDAC), the catalytic β subunit or the δ subunit of the F0F1-ATP synthase, mitochondrial cyclophilin, cytochrome c, and proteins encoded by the mitochondrial genome as revealed by [rho 0] cells. In contrast, actual cell killing was dependent upon select mitochondrial components including the β subunit of ATP synthase and mitochondrial genome-encoded proteins but not VDAC. The BCL-XL protection from either BAX-induced growth arrest or cell killing proved to be independent of mitochondrial components. Thus, BAX induces two cellular processes in yeast which can each be abrogated by BCL-XL: cell arrest, which does not require aspects of mitochondrial biochemistry, and cell killing, which does.

scholarly journals Kinetic coupling of the respiratory chain with ATP synthase, but not proton gradients, drives ATP production in cristae membranes

2020 ◽  
Vol 117 (5) ◽  
pp. 2412-2421 ◽  
Author(s):  
Alexandra Toth ◽  
Axel Meyrat ◽  
Stefan Stoldt ◽  
Ricardo Santiago ◽  
Dirk Wenzel ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Atp Synthase ◽  
Atp Synthesis ◽  
Proton Pumping ◽  
Yeast Cells ◽  
Synthesis Rate ◽  
Proton Gradients ◽  
Inner Membrane ◽  
Ph Values ◽  
Kinetic Coupling

Mitochondria have a characteristic ultrastructure with invaginations of the inner membrane called cristae that contain the protein complexes of the oxidative phosphorylation system. How this particular morphology of the respiratory membrane impacts energy conversion is currently unknown. One proposed role of cristae formation is to facilitate the establishment of local proton gradients to fuel ATP synthesis. Here, we determined the local pH values at defined sublocations within mitochondria of respiring yeast cells by fusing a pH-sensitive GFP to proteins residing in different mitochondrial subcompartments. Only a small proton gradient was detected over the inner membrane in wild type or cristae-lacking cells. Conversely, the obtained pH values did barely permit ATP synthesis in a reconstituted system containing purified yeast F1F0 ATP synthase, although, thermodynamically, a sufficiently high driving force was applied. At higher driving forces, where robust ATP synthesis was observed, a P-side pH value of 6 increased the ATP synthesis rate 3-fold compared to pH 7. In contrast, when ATP synthase was coreconstituted with an active proton-translocating cytochrome oxidase, ATP synthesis readily occurred at the measured, physiological pH values. Our study thus reveals that the morphology of the inner membrane does not influence the subcompartmental pH values and is not necessary for robust oxidative phosphorylation in mitochondria. Instead, it is likely that the dense packing of the oxidative phosphorylation complexes in the cristae membranes assists kinetic coupling between proton pumping and ATP synthesis.

scholarly journals Control of respiration and ATP synthesis in mammalian mitochondria and cells

1992 ◽  
Vol 284 (1) ◽  
pp. 1-13 ◽  
Author(s):  
G C Brown
Keyword(s):  
Energy Metabolism ◽  
Oxidative Phosphorylation ◽  
Respiratory Chain ◽  
Atp Synthase ◽  
Energy Charge ◽  
Atp Synthesis ◽  
Basic Mechanism ◽  
Proton Leak ◽  
Control Of Respiration ◽  
Phosphorylation Potential

We have seen that there is no simple answer to the question ‘what controls respiration?’ The answer varies with (a) the size of the system examined (mitochondria, cell or organ), (b) the conditions (rate of ATP use, level of hormonal stimulation), and (c) the particular organ examined. Of the various theories of control of respiration outlined in the introduction the ideas of Chance & Williams (1955, 1956) give the basic mechanism of how respiration is regulated. Increased ATP usage can cause increased respiration and ATP synthesis by mass action in all the main tissues. Superimposed on this basic mechanism is calcium control of matrix dehydrogenases (at least in heart and liver), and possibly also of the respiratory chain (at least in liver) and ATP synthase (at least in heart). In many tissues calcium also stimulates ATP usage directly; thus calcium may stimulate energy metabolism at (at least) four possible sites, the importance of each regulation varying with tissue. Regulation of multiple sites may occur (from a teleological point of view) because: (a) energy metabolism is branched and thus proportionate regulation of branches is required in order to maintain constant fluxes to branches (e.g. to proton leak or different ATP uses); and/or (b) control over fluxes is shared by a number of reactions, so that large increases in flux requires stimulation at multiple sites because each site has relatively little control. Control may be distributed throughout energy metabolism, possibly due to the necessity of minimizing cell protein levels (see Brown, 1991). The idea that energy metabolism is regulated by energy charge (as proposed by Atkinson, 1968, 1977) is misleading in mammals. Neither mitochondrial ATP synthesis nor cellular ATP usage is a unique function of energy charge as AMP is not a significant regulator (see for example Erecinska et al., 1977). The near-equilibrium hypothesis of Klingenberg (1961) and Erecinska & Wilson (1982) is partially correct in that oxidative phosphorylation is often close to equilibrium (apart from cytochrome oxidase) and as a consequence respiration and ATP synthesis are mainly regulated by (a) the phosphorylation potential, and (b) the NADH/NAD+ ratio. However, oxidative phosphorylation is not always close to equilibrium, at least in isolated mitochondria, and relative proximity to equilibrium does not prevent the respiratory chain, the proton leak, the ATP synthase and ANC having significant control over the fluxes. Thus in some conditions respiration rate correlates better with [ADP] than with phosphorylation potential, and may be relatively insensitive to mitochondrial NADH/NAD+ ratio.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Studies of energy-linked reactions. Net synthesis of adenosine triphosphate by isolated adenosine triphosphate synthase preparations: a role for lipoic acid and unsaturated fatty acids

1976 ◽  
Vol 160 (3) ◽  
pp. 809-812 ◽  
Author(s):  
D E Griffiths
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Oxidative Phosphorylation ◽  
Adenosine Triphosphate ◽  
Atp Synthase ◽  
Lipoic Acid ◽  
Adenosine Triphosphatase ◽  
Unsaturated Fatty Acids ◽  
Atp Synthesis ◽  
Substrate Level

ATP synthase preparations [complex V, proton-translocatin ATPase (adenosine triphosphatase) and oligomycin-sensitive ATPase] contain stoicheiometric amounts of lipoic acid residues (up to 6mol of lipoic acid/mol of ATPase complex) and catalyse net ATP synthesis in an uncoupler-and oligomycin-sensitive reaction utilizing dihydrolipoate, oleoyl-CoA and oleic acid, or in a reaction utilizing oleoyl-S-lipoate. The terminal reactions of oxidative phosphorylation are thus analogous to those of substrate-level phosphorylation.

scholarly journals Dye-ligand chromatographic purification of intact multisubunit membrane protein complexes: application to the chloroplast H+-F0F1-ATP synthase

2000 ◽  
Vol 346 (1) ◽  
pp. 41-44
Author(s):  
Holger SEELERT ◽  
Ansgar POETSCH ◽  
Meino ROHLFS ◽  
Norbert A. DENCHER
Keyword(s):  
Membrane Protein ◽  
Phosphatidic Acid ◽  
Ammonium Sulphate ◽  
Atp Synthase ◽  
Protein Complex ◽  
Protein Complexes ◽  
Atp Synthesis ◽  
Chromatographic Purification ◽  
Membrane Protein Complexes ◽  
Fof1 Atp Synthase

n-Dodecyl-β-D-maltoside was used as a detergent to solubilize the ammonium sulphate precipitate of chloroplast FOF1-ATP synthase, which was purified further by dye-ligand chromatography. Upon reconstitution of the purified protein complex into phosphatidylcholine/phosphatidic acid liposomes, ATP synthesis, driven by an artificial ∆pH/∆ψ, was observed. The highest activity was achieved with ATP synthase solubilized in n-dodecyl-β-D-maltoside followed by chromatography with Red 120 dye. The optimal dye for purification with CHAPS was Green 5. All known subunits were present in the monodisperse proton-translocating ATP synthase preparation obtained from chloroplasts.

scholarly journals Perfect chemomechanical coupling of FoF1-ATP synthase

2017 ◽  
Vol 114 (19) ◽  
pp. 4960-4965 ◽  
Author(s):  
Naoki Soga ◽  
Kazuya Kimura ◽  
Kazuhiko Kinosita ◽  
Masasuke Yoshida ◽  
Toshiharu Suzuki
Keyword(s):  
Atp Synthase ◽  
Chemical Potential ◽  
Initial Rate ◽  
Coupling Efficiency ◽  
Atp Synthesis ◽  
Energy Yield ◽  
Coupling Mechanism ◽  
Chemomechanical Coupling ◽  
Base Transition ◽  
Fof1 Atp Synthase

FoF1-ATP synthase (FoF1) couples H+ flow in Fo domain and ATP synthesis/hydrolysis in F1 domain through rotation of the central rotor shaft, and the H+/ATP ratio is crucial to understand the coupling mechanism and energy yield in cells. Although H+/ATP ratio of the perfectly coupling enzyme can be predicted from the copy number of catalytic β subunits and that of H+ binding c subunits as c/β, the actual H+/ATP ratio can vary depending on coupling efficiency. Here, we report actual H+/ATP ratio of thermophilic Bacillus FoF1, whose c/β is 10/3. Proteoliposomes reconstituted with the FoF1 were energized with ΔpH and Δψ by the acid−base transition and by valinomycin-mediated diffusion potential of K+ under various [ATP]/([ADP]⋅[Pi]) conditions, and the initial rate of ATP synthesis/hydrolysis was measured. Analyses of thermodynamically equilibrated states, where net ATP synthesis/hydrolysis is zero, show linear correlation between the chemical potential of ATP synthesis/hydrolysis and the proton motive force, giving the slope of the linear function, that is, H+/ATP ratio, 3.3 ± 0.1. This value agrees well with the c/β ratio. Thus, chemomechanical coupling between Fo and F1 is perfect.

scholarly journals Functions of BCL-XLat the Interface between Cell Death and Metabolism

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Judith Michels ◽  
Oliver Kepp ◽  
Laura Senovilla ◽  
Delphine Lissa ◽  
Maria Castedo ◽  
...  
Keyword(s):  
Cell Death ◽  
Mitochondrial Permeability Transition ◽  
Atp Synthesis ◽  
Anion Channel ◽  
Permeability Transition ◽  
Short Review ◽  
Mitochondrial Outer Membrane ◽  
Voltage Dependent Anion Channel ◽  
Regulated Necrosis ◽  
Voltage Dependent

The BCL-2 homolog BCL-XL, one of the two protein products ofBCL2L1, has originally been characterized for its prominent prosurvival functions. Similar to BCL-2, BCL-XLbinds to its multidomain proapoptotic counterparts BAX and BAK, hence preventing the formation of lethal pores in the mitochondrial outer membrane, as well as to multiple BH3-only proteins, thus interrupting apical proapoptotic signals. In addition, BCL-XLhas been suggested to exert cytoprotective functions by sequestering a cytosolic pool of the pro-apoptotic transcription factor p53 and by binding to the voltage-dependent anion channel 1 (VDAC1), thereby inhibiting the so-called mitochondrial permeability transition (MPT). Thus, BCL-XLappears to play a prominent role in the regulation of multiple distinct types of cell death, including apoptosis and regulated necrosis. More recently, great attention has been given to the cell death-unrelated functions of BCL-2-like proteins. In particular, BCL-XLhas been shown to modulate a number of pathophysiological processes, including—but not limited to—mitochondrial ATP synthesis, protein acetylation, autophagy and mitosis. In this short review article, we will discuss the functions of BCL-XLat the interface between cell death and metabolism.

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