The Adenine Nucleotide Translocase: A Central Component of the Mitochondrial Permeability Transition Pore and Key Player in Cell Death

2003 ◽  
Vol 10 (16) ◽  
pp. 1507-1525 ◽  
Author(s):  
Andrew Halestrap ◽  
Catherine Brenner
Keyword(s):  
Cell Death ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Adenine Nucleotide Translocase ◽  
Central Component ◽  
Mitochondrial Permeability

scholarly journals The mitochondrial permeability transition pore and its role in cell death

1999 ◽  
Vol 341 (2) ◽  
pp. 233-249 ◽  
Author(s):  
Martin CROMPTON
Keyword(s):  
Cell Death ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Adenine Nucleotide Translocase ◽  
Mitochondrial Permeability ◽  
Ischaemia Reperfusion ◽  
Pore Opening

This article reviews the involvement of the mitochondrial permeability transition pore in necrotic and apoptotic cell death. The pore is formed from a complex of the voltage-dependent anion channel (VDAC), the adenine nucleotide translocase and cyclophilin-D (CyP-D) at contact sites between the mitochondrial outer and inner membranes. In vitro, under pseudopathological conditions of oxidative stress, relatively high Ca2+ and low ATP, the complex flickers into an open-pore state allowing free diffusion of low-Mr solutes across the inner membrane. These conditions correspond to those that unfold during tissue ischaemia and reperfusion, suggesting that pore opening may be an important factor in the pathogenesis of necrotic cell death following ischaemia/reperfusion. Evidence that the pore does open during ischaemia/reperfusion is discussed. There are also strong indications that the VDAC-adenine nucleotide translocase-CyP-D complex can recruit a number of other proteins, including Bax, and that the complex is utilized in some capacity during apoptosis. The apoptotic pathway is amplified by the release of apoptogenic proteins from the mitochondrial intermembrane space, including cytochrome c, apoptosis-inducing factor and some procaspases. Current evidence that the pore complex is involved in outer-membrane rupture and release of these proteins during programmed cell death is reviewed, along with indications that transient pore opening may provoke ‘accidental’ apoptosis.

scholarly journals Role of critical thiol groups on the matrix surface of the adenine nucleotide translocase in the mechanism of the mitochondrial permeability transition pore

2002 ◽  
Vol 367 (2) ◽  
pp. 541-548 ◽  
Author(s):  
Gavin P. McSTAY ◽  
Samantha J. CLARKE ◽  
Andrew P. HALESTRAP
Keyword(s):  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Adenine Nucleotide ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
Adenine Nucleotide Translocase ◽  
Cross Linking ◽  
Thiol Groups ◽  
Mitochondrial Permeability ◽  
Pre Treatment

Opening of the mitochondrial permeability transition pore (MPTP) is sensitized to [Ca2+] by oxidative stress (diamide) and phenylarsine oxide (PAO). We have proposed that both agents cross-link two thiol groups on the adenine nucleotide translocase (ANT) involved in ADP and cyclophilin-D (CyP-D) binding. Here, we demonstrate that blocking Cys160 with 80μM eosin 5-maleimide (EMA) or 500μM N-ethylmaleimide (NEM) greatly decreased ADP inhibition of the MPTP. The ability of diamide, but not PAO, to block ADP inhibition of the MPTP was antagonized by treatment of mitochondria with 50μM NEM to alkylate matrix glutathione. Binding of detergent-solubilized ANT to a PAO-affinity matrix was prevented by pre-treatment of mitochondria with diamide, EMA or PAO, but not NEM. EMA binding to the ANT in submitochondrial particles (SMPs) was prevented by pre-treatment of mitochondria with either PAO or diamide, implying that both agents modify Cys160. Diamide and PAO pre-treatments also inhibited binding of solubilized ANT to a glutathione S-transferase—CyP-D affinity column, both effects being blocked by 100μM EMA. Intermolecular cross-linking of adjacent ANT molecules via Cys57 by copper phenanthroline treatment of SMPs was abolished by pre-treatment of mitochondria with diamide and PAO, but not with EMA. Our data suggest that PAO and diamide cause intramolecular cross-linking between Cys160 and Cys257 directly (not antagonized by 50μM NEM) or using glutathione (antagonized by 50μM NEM) respectively. This cross-linking stabilizes the ‘c’ conformation of the ANT, reducing the reactivity of Cys57, while enhancing CyP-D binding to the ANT and antagonizing ADP binding. The two effects together greatly sensitize the MPTP to [Ca2+].

Abstract 321: Obesity Causes Enhanced Sensitivity Of The Mitochondrial Permeability Transition Pore

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Judith Bernal-Ramírez ◽  
Adriana Riojas-Hernández ◽  
Flor E Morales-Marroquín ◽  
Elvía M Domínguez-Barragán ◽  
David Rodríguez-Mier ◽  
...  
Keyword(s):  
Cell Death ◽  
Cardiac Dysfunction ◽  
Mitochondrial Permeability Transition Pore ◽  
Mitochondrial Permeability Transition ◽  
Permeability Transition Pore ◽  
Permeability Transition ◽  
H2o2 Production ◽  
Mitochondrial Permeability ◽  
Removal Capacity ◽  
Mptp Opening

Several mechanisms have been implicated in heart failure (HF) development due to obesity, including altered Ca2+ homeostasis and mitochondrial increased reactive oxygen species (ROS). Besides their metabolic role, mitochondria are important cell death regulators, since their disruption induces apoptosis. The mitochondrial permeability transition pore (MPTP) formation is key in this process. Ca2+ and ROS are known inducers of MPTP, and mitochondria are the main ROS generators. However, it has not been demonstrated that MPTP formation is involved in cardiac cell death due to obesity. Therefore, the aim of this work was to determine whether Ca2+ alterations and/or MPTP opening underlie cardiac dysfunction. We used obese Zucker fa/fa rats (32 weeks old), displaying concentric hypertrophy and cardiac dysfunction. We measured: i) Systolic and diastolic Ca2+ signaling in isolated myocytes, in basal conditions and upon β-adrenergic stimulation (β-AS), and ii) in vitro mitochondrial function: respiration, ROS production and MPTP opening. We found that the main alteration in Ca2+ signaling in fa/fa myocytes was a decrease in SERCA Ca2+ removal capacity, since Ca2+ transient amplitude and spark frequency were unchanged. Furthermore, in fa/fa myocytes, β-AS response was preserved. On the other hand, fa/fa mitochondria respiration, in state 3 decreased, but was unchanged in state 4, when glutamate/malate were used as substrate, resulting in an small decrease in respiratory control. In addition, fa/fa mitochondria were more sensitive to MPTP opening, induced by Ca2+ and carboxyatractiloside (CAT). Moreover, fa/fa mitochondria showed increased H2O2 production, and in exposed thiol groups in the adenine nucleotide translocase, a regulatory MPTP component. Since Ca2+ signaling is relatively normal in fa/fa cells, it does not seem to be the main contributor to the cardiac contractile dysfunction. However, given that fa/fa mitochondria showed decrease respiratory performance, were more susceptible to MPTP opening, and showed enhanced H2O2 production. We conclude that fa/fa mitochondria were more vulnerable to enhanced oxidative stress, causing MPTP opening, which could be exacerbated by SERCA slower Ca2+ removal capacity, leading to myocyte apoptosis.

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