Potential role of subunit c of F0F1-ATPase and subunit c of storage body in the mitochondrial permeability transition. Effect of the phosphorylation status of subunit c on pore opening.

TitlePotential role of subunit c of F0F1-ATPase and subunit c of storage body in the mitochondrial permeability transition. Effect of the phosphorylation status of subunit c on pore opening.
Publication TypeJournal Article
Year of Publication2014
AuthorsAzarashvili, T, Odinokova, I, Bakunts, A, Ternovsky, V, Krestinina, O, Tyynelä, J, Saris, N-ELeo
JournalCell Calcium
Volume55
Issue2
Pagination69-77
Date Published2014 Feb
ISSN1532-1991
KeywordsAnimals, Calcium, Cyclosporine, Kinetics, Lipid Bilayers, Male, Membrane Potential, Mitochondrial, Mitochondria, Liver, Mitochondrial Membrane Transport Proteins, Mitochondrial Swelling, Phosphorylation, Protein Binding, Protein Subunits, Proton-Translocating ATPases, Rats, Rats, Wistar, Sheep
Abstract

Phosphorylated and non-phosphorylated forms of the F0F1-ATPase subunit c from rat liver mitochondria (RLM) were purified and their effect on the opening of the permeability transition pore (mPTP) was investigated. Addition of dephosphorylated subunit c to RLM induced mitochondrial swelling, decreased the membrane potential and reduced the Ca2+ uptake capacity, which was prevented by cyclosporin A. The same effect was observed in the presence of storage subunit c purified from livers of sheep affected with ceroid lipofuscinosis. In black-lipid bilayer membranes subunit c increased the conductance due to formation of single channels with fast and slow kinetics. The dephosphorylated subunit c formed channels with slow kinetics, i.e. the open state being of significantly longer duration than in the case of channels formed by the phosphorylated form that had short life spans and fast kinetics. The channels formed were cation-selective more so with the phosphorylated form. Subunit c of rat liver mitochondria was able to bind Ca2+. Collectively, the data allowed us to suppose that subunit c F0F1-ATPase might be a structural/regulatory component of mPTP exerting its role in dependence on phosphorylation status.

DOI10.1016/j.ceca.2013.12.002
Alternate JournalCell Calcium
Citation Key10.1016/j.ceca.2013.12.002
PubMed ID24380588