Properties of the permeability transition in VDAC1(-/-) mitochondria.
Opening of the permeability transition pore (PTP), a high-conductance mitochondrial channel, causes mitochondrial dysfunction with Ca2+ deregulation, ATP depletion, release of pyridine nucleotides and of mitochondrial apoptogenic proteins. Despite major efforts, the molecular nature of the PTP remains elusive. A compound library screening led to the identification of a novel high affinity PTP inhibitor (Ro 68-3400), which labeled a approximately 32 kDa protein that was identified as isoform 1 of the voltage-dependent anion channel (VDAC1) [A.M. Cesura, E. Pinard, R. Schubenel, V. Goetschy, A. Friedlein, H. Langen, P. Polcic, M.A. Forte, P. Bernardi, J.A. Kemp, The voltage-dependent anion channel is the target for a new class of inhibitors of the mitochondrial permeability transition pore. J. Biol. Chem. 278 (2003) 49812-49818]. In order to assess the role of VDAC1 in PTP formation and activity, we have studied the properties of mitochondria from VDAC1(-/-) mice. The basic properties of the PTP in VDAC1(-/-) mitochondria were indistinguishable from those of strain-matched mitochondria from wild-type CD1 mice, including inhibition by Ro 68-3400, which labeled identical proteins of 32 kDa in both wild-type and VDAC1(-/-) mitochondria. The labeled protein could be separated from all VDAC isoforms. While these results do not allow to exclude that VDAC is part of the PTP, they suggest that VDAC is not the target for PTP inhibition by Ro 68-3400.
Krauskopf
Alexandra
A
Department of Biomedical Sciences, University of Padova, Viale Giuseppe Colombo 3, I-35121 Padova, Italy.
Eriksson
Ove
O
Craigen
William J
WJ
Forte
Michael A
MA
Bernardi
Paolo
P
D000818:Animals; D001152:Arsenicals / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D003986:Dibenzocycloheptenes / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D051379:Mice; D018345:Mice, Knockout; D008930:Mitochondria, Liver / Q000187:drug effects / Q000502:physiology*; D033681:Mitochondrial Membrane Transport Proteins / Q000502:physiology*; D051336:Mitochondrial Membranes / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling; D013141:Spiro Compounds / Q000494:pharmacology; D014451:Ubiquinone / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology; D050995:Voltage-Dependent Anion Channel 1 / Q000235:genetics / Q000502:physiology*
D001152:Arsenicals; D003986:Dibenzocycloheptenes; D004791:Enzyme Inhibitors; D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; C480229:Ro 68-3400; D013141:Spiro Compounds; D014475:Uncoupling Agents; C494763:Vdac1 protein, mouse; C029341:oxophenylarsine; D014451:Ubiquinone; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D050995:Voltage-Dependent Anion Channel 1; D005033:Ethylmaleimide; D002118:Calcium