Export of biomolecules from mitochondria

Mitochondrion is cellular organelle evolved from the endosymbiotic bacteria. Because of its bacterial origin mitochondrion has a number of unique properties and metabolic pathways. Mitochondria or its reduced forms are present in all eukaryotic organisms except a single exception. During the course of evolution most of mitochondrial DNA was transferred to the nucleus. Despite this, mitochondria still encode several proteins that are part of the electron transport chain and the ATP synthase. These proteins are transported from the mitochondrial matrix into the inner mitochondrial membrane. Misfolded proteins of the inner membrane are degraded by mitochondrial proteases, which leads to the release of generated peptides. Fe-S clusters are assembled in the mitochondrial matrix. Still unknown molecule, which is product of ISC pathway is transported into cytosol and participates in the assembly of cytosolic and nuclear iron-sulfur proteins. Other transport pathway ensures the exchange of lipids between the endoplasmic reticulum and mitochondria. Both mitochondrial membranes have different lipid composition. To maintain their properties specific lipid transport is required between the two mitochondrial membranes. This transport pathway is also used for the lipid synthesis in the inner mitochondrial membrane