Induction of permeability of the inner membrane of yeast mitochondria

Abstract

The current view on apoptosis is given, with a special emphasis placed on apoptosis in yeasts. Induction of a nonspecific permeability transition pore (mPTP) in mammalian and yeast mitochondria is described, particularly in mitochondria from Yarrowia lipolytica and Dipodascus (Endomyces) magnusii yeasts, which are aerobes possessing the fully competent respiratory chain with all three points of energy conservation and well-structured mitochondria. They were examined for their ability to induce an elevated permeability transition of the inner mitochondrial membrane, being subjected to virtually all conditions known to induce the mPTP in animal mitochondria. Yeast mitochondria do not form Ca2+-dependent pores, neither the classical Ca2+/P(i)-dependent, cyclosporin A-sensitive pore even under de-energization of mitochondria or depletion of the intramitochondrial nucleotide pools, nor a pore induced in mammalian mitochondria upon concerted action of moderate Ca2+ concentrations (in the presence of the Ca2+ ionophore ETH129) and saturated fatty acids. No pore formation was found in yeast mitochondria in the presence of elevated phosphate concentrations at acidic pH values. It is concluded that the permeability transition in yeast mitochondria is not coupled with Ca2+ 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

“…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.…”

Recent Results in Alamethicin Research

“…Although the configuration of pores formed by ALM Q7K analogue differed from that observed previously for ALM [61], regarding the transmembrane orientations of peptides, the helicity of ALM Q7K was found to be comparable to that calculated for ALM. In a further study, MD simulations were carried out by [68] reported that ALM induced large-amplitude swelling of mitochondria and the formation of 1 nm channels in mitochondrial membranes permeable to divalent cations and low-molecular weight compounds. Kuharczyk et al…”

A distinct sequence in the adenine nucleotide translocase from Artemia franciscana embryos is associated with insensitivity to bongkrekate and atypical effects of adenine nucleotides on Ca2+ uptake and sequestration

“…In contrast, cyclosporin A failed to afford protection from the PTP in wheat ( Triticum aestivum L.) mitochondria, even in the presence of dithioerythritol [14]. Furthermore, no Ca 2+ ‐induced PTP could be found in mitochondria from the yeast Endomyces magnusii [15–17]. Likewise, no Ca 2+ ‐induced PTP could be found in mitochondria from embryos of the crustacean A. franciscana [18].…”