MITOCHONDRIAL MATRIX FRAGMENTATION AS A PROTECTION MECHANISM OF <i>Saccharomyces cerevisiae</i>
It is shown that separate fragments of the inner mitochondrial compartment (mitoplasts) can exist under a single non-fragmented outer membrane. Here we asked whether fragmentation of the inner mitochondria could prevent rupturing of the outer membrane and release of pro-apoptotic molecules from the mitochondrial intermembrane space into the cytoplasm during mitochondrial swelling. First, we showed that in <i>Saccharomyces cerevisiae </i>addition of amiodarone causes formation of electrically separate compartments within mitochondrial filaments. Moreover, amiodarone treatment of the ∆<i>ysp2 </i>mutant produced a higher proportion of cells with electrically discontinuous mitochondria than in the wild type, which correlated with the survival of cells. We confirmed the existence of separated mitoplasts under a single outer membrane using electron microscopy. Mitochondria with fragmented matrixes were also detected in cells of the stationary phase. Our data suggest that such a fragmentation acts as a protective mechanism of cells against stress.