Related Experiment Video
Updated: Aug 29, 2026

Assessment of Open Probability of the Mitochondrial Permeability Transition Pore in the Setting of Coenzyme Q Excess
Published on: June 1, 2022
Cyclophilin D, a component of the permeability transition-pore, is an apoptosis repressor
Alexis Schubert1, Stefan Grimm
1Max-Planck-Institute for Biochemistry, Martinsried, Germany.
Abstract:
The permeability transition (PT)-pore is an important proapoptotic protein complex in mitochondria. Although it is activated by many signals for apoptosis induction, the role of its various subunits in cell death induction has remained largely unknown. We found that of its components, only the voltage-dependent anion channel in the outer mitochondrial membrane and the adenine nucleotide translocator-1 (ANT-1), a PT-pore subunit of the inner membrane, are apoptosis inducers. We also report that ANT-1's direct interactor, cyclophilin D, can specifically repress ANT-1-induced apoptosis. In addition, cotransfection experiments revealed that for a diverse range of apoptosis inducers, cyclophilin D shows the same repression profile as the compound bongkrekic acid, a specific inhibitor of the PT-pore. This activity seems to be independent of its chaperone activity, the only known function of cyclophilin D to date. Importantly, cyclophilin D is specifically up-regulated in human tumors of the breast, ovary, and uterus, suggesting that inhibition of the PT-pore via up-regulation of cyclophilin D plays a role in tumorigenesis.
Related Concept Videos
The Intrinsic Apoptotic Pathway
The Extrinsic Apoptotic Pathway
Phagocytosis of Apoptotic Cells
Normal cells contain receptors that prevent them from being recognized by phagocytes.
Anaphase Promoting Complex
Caspases
Apoptosis

