Does FOF1 ATP synthase form the mitochondrial permeability transition pore in plants?

Recently, it has been proposed that in mammals the mitochondrial permeability transition pore (PTP) is actually formed by FOF1 ATP synthase dimers (Giorgio et al., 2013). The permeability transition in plant mitochondria is still elusive and has been evidenced only in few peculiar cases (Vianello et al., 2012). This research aimed at comparing the components and activity of plant mitochondria ATP synthase to its mammalian counterpart. Purified mitochondria were subjected to BN-PAGE, the gel was stained for ATPase activity and the active bands, after immunodecoration with specific primary antibodies, confirmed the presence of CyPD and OSCP associated to ATP synthase. ATP synthase was also characterized in sub-mitochondrial particles, evaluating its activity as both ATP hydrolysis and proton pumping activity. The scalar ATPase activity was dependent on divalent ions, while ATP induced the formation of a proton gradient only in the presence of Mg2+ and Mn2+, being Ca2+ ineffective. Our results show that ATP synthase in plant mitochondria possesses similar structural and functional properties with respect to the animal counterpart. Supported by MIUR grant PRIN 2010CSJX4F.