Yeast Mitochondrial Derived Vesicles (MDVs) have membrane potential and contain a functional ATP synthase

Mitochondria are responsible for the production of energy and for essential metabolic pathways in the cell, as well as fundamental processes such as apoptosis and aging. Interestingly, while the import machinery of proteins into mitochondria is thoroughly understood, there is currently no known protein export mechanism from mitochondria. Vesicular transport is a means of inter-organellar communication, and in fact cells release vesicles in order to shuttle lipids, proteins, RNA and DNA between one another. Here we show for the first time that functional mitochondria, isolated from Saccharomyces cerevisiae can release vesicles, independent of the fission machinery. Mitochondrial secreted vesicles are relatively uniform in size, of about 100nm and carry a selection of cargo; only certain proteins are carried by these vesicles, of which some are matrix soluble and some are membrane proteins. We further demonstrate that yeast MDVs harbor a membrane potential, a functional ATP synthase complex, produce ATP, and fuse with naive mitochondria. We suggest, that MDVs may have a function in organellar protein export, ATP production ability of damaged mitochondria and organelle-communication.