Study on the relationship between calcium-induced calcium release from mitochondria and PTP opening.
The permeability transition pore (PTP) is central for mitochondria function. PTP either open in low-conductance state to carry out mCICR (Ca2+-induced Ca2+ release from mitochondria) and play roles in cell phsyiological activities or open in high-conductance conformation to release harmful substances and play important roles in cell pathological responses and apoptosis. The results of study on the relationship between mCICR and PTP opening show Ca2+ concentrations but not the Ca2+ delivery mode determined the occurrence of mCICR or PTP opening. Ca2+-induced PTP opening began with and depended on mCICR. mCICR was a prerequisite for H2O2 and As2O3-induced PTP opening. The results indicated that the PTP opening was determined by Ca2+ stimulation intensity but not mode. PTP could switch from low- to high-conductance conformation and the PTP open by high-conductance began with low-conductance state. mCICR is necessary for Ca2+-dependent PTP opening. Our data suggested also that it would be possible to control cellular responses first by modulating mCICR, then by regulating PTP opening.
Huang
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National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing, China.
Zhai
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D
Huang
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D000818:Animals; D002118:Calcium / Q000378:metabolism*; D005260:Female; D005453:Fluorescence; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000378:metabolism / Q000502:physiology*; D008564:Membrane Potentials; D008930:Mitochondria, Liver / Q000378:metabolism / Q000502:physiology*; D010539:Permeability; D051381:Rats; D017208:Rats, Wistar
D002118:Calcium