Induction of a non-specific permeability transition in mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts

Abstract

In this study we used tightly-coupled mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts, possessing a respiratory chain with the usual three points of energy conservation. High-amplitude swelling and collapse of the membrane potential were used as parameters for demonstrating induction of the mitochondrial permeability transition due to opening of a pore (mPTP). Mitochondria from Y. lipolytica, lacking a natural mitochondrial Ca(2+) uptake pathway, and from D. magnusii, harboring a high-capacitive, regulated mitochondrial Ca(2+) transport system (Bazhenova et al. J Biol Chem 273:4372-4377, 1998a; Bazhenova et al. Biochim Biophys Acta 1371:96-100, 1998b; Deryabina and Zvyagilskaya Biochemistry (Moscow) 65:1352-1356, 2000; Deryabina et al. J Biol Chem 276:47801-47806, 2001) were very resistant to Ca(2+) overload. However, exposure of yeast mitochondria to 50-100 microM Ca(2+) in the presence of the Ca(2+) ionophore ETH129 induced collapse of the membrane potential, possibly due to activation of the fatty acid-dependent Ca(2+)/nH(+)-antiporter, with no classical mPTP induction. The absence of response in yeast mitochondria was not simply due to structural limitations, since large-amplitude swelling occurred in the presence of alamethicin, a hydrophobic, helical peptide, forming voltage-sensitive ion channels in lipid membranes. Ca(2+)- ETH129-induced activation of the Ca(2+)/H(+)-antiport system was inhibited and prevented by bovine serum albumin, and partially by inorganic phosphate and ATP. We subjected yeast mitochondria to other conditions known to induce the permeability transition in animal mitochondria, i.e., Ca(2+) overload (in the presence of ETH129) combined with palmitic acid (Mironova et al. J Bioenerg Biomembr 33:319-331, 2001; Sultan and Sokolove Arch Biochem Biophys 386:37-51, 2001), SH-reagents, carboxyatractyloside (an inhibitor of the ADP/ATP translocator), depletion of intramitochondrial adenine nucleotide pools, deenergization of mitochondria, and shifting to acidic pH values in the presence of high phosphate concentrations. None of the above-mentioned substances or conditions induced a mPTP-like pore. It is thus evident that the permeability transition in yeast mitochondria is not coupled with Ca(2+) uptake and is differently regulated compared to the mPTP of animal mitochondria.

Role of charge screening and delocalization for lipophilic cation permeability of model and mitochondrial membranes

“…Mitochondria from Y. lipolytica cells were prepared as described previously (Kovaleva et al, 2009). They were fully active for at least 4 h when kept on ice.…”

“…1S, see Supplement). Respiring mitochondria maintained their ΔΨ for a long time without any swelling (Kovaleva et al, 2009). Tightly-coupled yeast mitochondria have some advantages over animal mitochondria as they lack a Ca 2+ /P i -dependent pore (Kovaleva et al, 2009(Kovaleva et al, , 2010Trendeleva et al, 2011aTrendeleva et al, , 2011b, a fact facilitating interpretation of the data obtained.…”

The mitochondrial permeability transition from yeast to mammals

“…Most classical studies of the PT were carried out in mitochondria obtained from mammals, although permeability changes, most notably those caused by ATP and substrates, have also been studied in yeast [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55]. In recent years, the growing interest on the PT in cell death has prompted an increasing number of studies in mitochondria from other organisms including plants [56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71], fish [72,73], amphibians [74,75], and the brine shrimp Artemia franciscana, a salt-and anoxia-tolerant organism that may represent an exception in that it apparently lacks a PT [76].…”

Inhibition of free radical scavenging enzymes affects mitochondrial membrane permeability transition during growth and aging of yeast cells

“…Using Y. lipolytica and D. magnusii Kovaleva and coauthors (Kovaleva et al 2009) have showed that the mitochondrial Δψ decreases in the presence of the ionophore of ETH129 if Са 2+ (50-100 μМ) is applied at low concentrations. This effect was a bit slowed by P i and АТР application.…”