Import of precursor proteins into isolated yeast mitochondria.

Mitochondria fulfill a large variety of metabolic tasks such as respiration, beta-oxidation, heme biosynthesis, ketone-body, or amino acid synthesis. In addition to their metabolic role, mitochondria are also key players in cellular apoptosis and participate in the generation of reactive oxygen species (ROS) and in calcium signaling. The proteins involved in these processes are mostly encoded by nuclear DNA and synthesized on cytosolic ribosomes. Accordingly, they have to be transported into mitochondria in order to reach the place where they act. The process of mitochondrial protein import can be reconstituted in vitro using isolated mitochondria and in vitro synthesized precursor proteins.