The mitochondrial permeability transition pore may comprise VDAC molecules

[摘要]

Electrophysiological records suggest that the pore responsible for the mitochondrial Ca²⁺-dependent permeability transition (FTP), identified as the mitochondrial megachannel (MMC) observed in patch-clamp experiments, may comprise two cooperating porin (VDAC) molecules. We have re-investigated the voltage dependence of the megachannel, which favors the closed state(s) at negative (physiological) transmembrane potentials. This behavior confirms that MMC corresponds to the permeabilization pore. As detailed in the accompanying paper [(1993) FEBS Lett. 330, 206-210] this voltage dependence resembles that of VDAC. Alpidem, a ligand of the mitochondrial benzodiazepine receptor, which reportedly comprises VDAC, the adenine nucleotide carrier and a third component, elicited currents from silent mitoplast patches, suggesting that the benzodiazepine receptor may be identical to the PTP/MMC.

[学科分类] 生物化学/生物物理

[关键词] Permeability transition;Patch clamp;VDAC;Mitochondrial megachannel;Mitochondrial benzodiazepine receptor;Rat liver mitochondria;pS;picoSiemens;nS;nanoSiemens;PT;permeability transition;PTP;permeability transition pore;MMC;mitochondrial megachannel;VDAC;voltage-dependent anion channel (mitochon-drial porin);ADC;adenine nucleotide carrier;mBzR;mitochondrial benzodiazepine receptor;HEPES;4-(2-hydroxyethyl)-1-piperazi-neethanesulfonic acid