scholarly journals Regulation of the mitochondrial ATP synthase in intact rat cardiomyocytes

1990 ◽  
Vol 266 (2) ◽  
pp. 355-361 ◽  
Author(s):  
A M Das ◽  
D A Harris
Keyword(s):  
Atp Synthase ◽  
Inhibitor Protein ◽  
Detectable Change ◽  
Rat Cardiomyocytes ◽  
Naturally Occurring ◽  
Regulator Protein ◽  
Mitochondrial Atp Synthase ◽  
Rat Heart Myocytes ◽  
Cultured Cardiomyocytes

The ATP synthase capacity of rat heart myocytes can be measured in sonicated cell suspensions and in sonicated preparations of cultured cardiomyocytes. This procedure allows the rapid measurement of mitochondrial function in response to changes in the metabolic status of the cell. In cultured myocytes, transitions in ATP synthase capacity (with no detectable change in cellular ATP concentration) accompany a change to anoxia or electrically stimulated contraction (rise of 70%). These changes are reversed on returning to the original conditions. Exposure of myocytes to low pH has little effect on basal ATP synthase capacity (down to values less than pH 6), but markedly affects cellular ATP levels and the response of the cells to anoxia and reoxygenation, possibly mimicking changes seen in ischaemic heart. Similar effects are seen in suspensions of freshly prepared myocytes, but these preparations are less stable and more pH-sensitive than are cells in culture. It is proposed that mitochondria in vivo are directly regulated at the level of the ATP synthase, and that a regulator protein, the naturally occurring inhibitor protein from mitochondria, may be responsible for this regulation.

scholarly journals Bedaquiline, an FDA-approved drug, inhibits mitochondrial ATP production and metastasis in vivo, by targeting the gamma subunit (ATP5F1C) of the ATP synthase

2021 ◽  
Author(s):  
Marco Fiorillo ◽  
Cristian Scatena ◽  
Antonio Giuseppe Naccarato ◽  
Federica Sotgia ◽  
Michael P. Lisanti
Keyword(s):  
Cell Migration ◽  
Treatment Failure ◽  
Atp Synthase ◽  
Atp Depletion ◽  
Multi Drug Resistance ◽  
Gamma Subunit ◽  
Primary Tumors ◽  
Atp Production ◽  
Mitochondrial Atp Synthase

AbstractHere, we provide evidence that high ATP production by the mitochondrial ATP-synthase is a new therapeutic target for anticancer therapy, especially for preventing tumor progression. More specifically, we isolated a subpopulation of ATP-high cancer cells which are phenotypically aggressive and demonstrate increases in proliferation, stemness, anchorage-independence, cell migration, invasion and multi-drug resistance, as well as high antioxidant capacity. Clinically, these findings have important implications for understanding treatment failure and cancer cell dormancy. Using bioinformatic analysis of patient samples, we defined a mitochondrial-related gene signature for metastasis, which features the gamma-subunit of the mitochondrial ATP-synthase (ATP5F1C). The relationship between ATP5F1C protein expression and metastasis was indeed confirmed by immunohistochemistry. Next, we used MDA-MB-231 cells as a model system to functionally validate these findings. Importantly, ATP-high MDA-MB-231 cells showed a nearly fivefold increase in metastatic capacity in vivo. Consistent with these observations, ATP-high cells overexpressed (i) components of mitochondrial complexes I–V, including ATP5F1C, and (ii) markers associated with circulating tumor cells (CTCs) and metastasis, such as EpCAM and VCAM1. Knockdown of ATP5F1C expression significantly reduced ATP-production, anchorage-independent growth, and cell migration, as predicted. Similarly, therapeutic administration of the FDA-approved drug, Bedaquiline, downregulated ATP5F1C expression in vitro and prevented spontaneous metastasis in vivo. In contrast, Bedaquiline had no effect on the growth of non-tumorigenic mammary epithelial cells (MCF10A) or primary tumors in vivo. Taken together, our results suggest that mitochondrial ATP depletion is a new therapeutic strategy for metastasis prophylaxis, to avoid treatment failure. In summary, we conclude that mitochondrial ATP5F1C is a promising new biomarker and molecular target for future drug development, for the prevention of metastatic disease progression.

Regulation of Mitochondrial ATP Synthase Activity in Human Myocardium

1998 ◽  
Vol 94 (5) ◽  
pp. 499-504 ◽  
Author(s):  
Anibh M. Das
Keyword(s):  
Atp Synthase ◽  
Energy Demand ◽  
Calcium Concentration ◽  
Human Myocardium ◽  
Heart Mitochondria ◽  
Biopsy Material ◽  
Rat Cardiomyocytes ◽  
Metabolic States ◽  
Mitochondrial Atp Synthase ◽  
Metabolic Conditions

1. In previous studies regulation of the F1F0-ATPase of mitochondrial complex V (ATP synthase) has been demonstrated in rat cardiomyocytes, canine mycocardium and skeletal muscle from children. The aim of the present study was to examine regulation of ATP synthase in human myocardium in response to different metabolic states. 2. Biopsy material was obtained from 10 children undergoing cardiac surgery. Mitochondria in the post-nuclear supernatant were incubated under different metabolic conditions for 15 min and then broken by sonication. ATP synthase was measured spectrophotometrically using a coupled enzyme assay. 3. ATP synthase can be rapidly measured in sonicated preparations of heart mitochondria from children. We show that direct regulation at the level of ATP synthase occurs in these mitochondria. ATP synthase capacity is decreased in response to blocking of the respiratory chain by cyanide (mimicking anoxia) or uncoupling of mitochondria, falling to 76% and 66% of control values respectively. Upregulation of ATP synthase can be demonstrated in heart mitochondria when the calcium concentration in the incubation medium is increased to 5 μM (130% of control). 4. ATP synthase is actively regulated in heart mitochondria from children. The enzyme is upregulated in response to increased calcium. This transition may reflect the increased energy demand when cardiac workload is increased.

scholarly journals ATP synthase subunit c expression: physiological regulation of the P1 and P2 genes

1997 ◽  
Vol 323 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Ulf ANDERSSON ◽  
Josef HOUŠTĚK ◽  
Barbara CANNON
Keyword(s):  
Thyroid Hormone ◽  
Cold Acclimation ◽  
Atp Synthase ◽  
Hormone Treatment ◽  
Rat Tissues ◽  
Mrna Levels ◽  
Subunit C ◽  
Brown Adipose ◽  
Mitochondrial Atp Synthase

Pre-translational regulation of subunit c has been suggested to control the biosynthesis of mitochondrial ATP synthase (ATPase) in brown adipose tissue (BAT). Subunit c is encoded by the genes P1 and P2, which encode identical mature proteins. We have determined here the levels of P1 and P2 mRNAs in different tissues, in response to cold acclimation in rats, during ontogenic development of BAT in hamsters, and following thyroid hormone treatment in rat BAT and liver. Quantitative ribonuclease protection analysis showed that both the P1 and P2 mRNAs were present in all rat tissues measured. Their total amount in each tissue corresponded well with the ATPase content of that tissue. While the P1/P2 mRNA ratio is high in ATPase-rich tissues, the P2 mRNA dominates in tissues with less ATPase. Cold acclimation affects P1 but not P2 gene expression in rat BAT. A rapid and transient increase in P1 mRNA is followed by sustained depression, which is accompanied by a decrease in ATPase content. Similarly, ontogenic suppression of ATPase content in hamster BAT was accompanied by suppression of the P1 mRNA levels, while P2 expression was virtually unchanged. Furthermore, when hypothyroid rats were treated with thyroid hormone, the steady-state level of P1 but not of P2 mRNA was significantly increased in liver. BAT was unaffected. We conclude that the P1 and P2 genes for subunit c are differentially regulated in vivo. While the P2 gene is expressed constitutively, the P1 gene responds to different physiological stimuli as a means of modulating the relative content of ATP synthase.

Inhibitors of the catalytic domain of mitochondrial ATP synthase

2006 ◽  
Vol 34 (5) ◽  
pp. 989-992 ◽  
Author(s):  
J.R. Gledhill ◽  
J.E. Walker
Keyword(s):  
Atp Synthase ◽  
Binding Sites ◽  
Catalytic Domain ◽  
Structural Studies ◽  
Inhibitor Protein ◽  
X Ray ◽  
F1 Atpase ◽  
X Ray Crystallography ◽  
Mitochondrial Atp Synthase ◽  
Natural Inhibitor

An understanding of the mechanism of ATP synthase requires an explanation of how inhibitors act. The catalytic F1-ATPase domain of the enzyme has been studied extensively by X-ray crystallography in a variety of inhibited states. Four independent inhibitory sites have been identified by high-resolution structural studies. They are the catalytic site, and the binding sites for the antibiotics aurovertin and efrapeptin and for the natural inhibitor protein, IF1.

scholarly journals A Family of Glycosylated Macrolides Selectively Target Energetic Vulnerabilities in Leukemia

2021 ◽  
Author(s):  
Benjamin J Reisman ◽  
Hui Guo ◽  
Haley E Ramsey ◽  
Madison T Wright ◽  
Bradley I Reinfeld ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Molecular Mechanism ◽  
Atp Synthase ◽  
Mechanism Of Action ◽  
Transformed Cells ◽  
Resistance Mutations ◽  
Selective Cytotoxicity ◽  
Binding Interface ◽  
Mitochondrial Atp Synthase

Cancer cells have long been recognized to exhibit unique bioenergetic requirements. The apoptolidin family of glycomacrolides are distinguished by their selective cytotoxicity towards oncogene transformed cells, yet their molecular mechanism remains uncertain. We used photoaffinity analogs of the apoptolidins to identify the F1 subcomplex of mitochondrial ATP synthase as the target of apoptolidin A. CryoEM of apoptolidin and ammocidin-ATP synthase complexes revealed a novel shared mode of inhibition that was confirmed by deep mutational scanning of the binding interface to reveal resistance mutations which were confirmed using CRISPR-Cas9. Ammocidin A was found to suppress leukemia progression in vivo at doses that were tolerated with minimal toxicity. The combination of cellular, structural, mutagenesis, and in vivo evidence define the mechanism of action of apoptolidin family glycomacrolides and establish a path to address OXPHOS-dependent cancers.

Synthesis and hydrolysis of ATP by the mitochondrial ATP synthase

1988 ◽  
Vol 66 (7) ◽  
pp. 677-682 ◽  
Author(s):  
M. Tuena de Gômez-Puyou ◽  
Orlando B. Martins ◽  
A. Gômez-Puyou
Keyword(s):  
Atp Synthase ◽  
Atp Hydrolysis ◽  
Atp Synthesis ◽  
Control Synthesis ◽  
Inhibitor Protein ◽  
Atpase Inhibitor ◽  
Mitochondrial Atp Synthase ◽  
High Concentrations ◽  
Hydrolysis Of

A brief summary of the factors that control synthesis and hydrolysis of ATP by the mitochondrial H+-ATP synthase is made. Particular emphasis is placed on the role of the natural ATPase inhibitor protein. It is clear from the existing data obtained with a number of agents that there is no correlation between variations of the rate of ATP hydrolysis and ATP synthesis as driven by respiration. The mechanism by which each condition differentially affects the two activities is not entirely known. For the case of the natural ATPase inhibitor protein, it appears that the protein controls the kinetics of the enzyme. This control seems essential for achieving maximal accumulation of ATP during electron transport in systems that contain relatively high concentrations of ATP.

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