Mitochondrial transport proteins: Highly dynamic integral membrane proteins required for the translocation of metabolites and cofactors, key to the function of the mitochondrion

The outer membrane of mitochondria is permeable for small molecules as it contains large pores, but the inner membrane, which forms cristae, is tightly sealed. A large number of different molecules need to traverse the inner membrane to link the biochemical pathways of the cytosol and mitochondria and for cellular processes. Among these compounds are keto acids derived from sugars and fatty acids derived from fat, which are oxidised inside mitochondria to generate the cellular fuel ATP. Amino acids, derived from protein, also enter mitochondria, where they are broken down, interconverted, or used in protein synthesis. Many vitamins are required in the mitochondrial matrix as they act as co-factors for many mitochondrial enzymes. Finally, nucleotides, which are required for replication and transcription of mitochondrial DNA, also need to traverse the inner membrane. More than 60 different transport proteins are present in the mitochondrial inner membrane to facilitate the translocation of these compounds. They belong to different protein families, such as the ABC transporter family, the mitochondrial pyruvate carrier family, and the mitochondrial carrier family. The function of many of them has not been established. We are interested in studying their role in cellular metabolism and human physiology. We would also like to establish how they work in order to identify the molecular cause for the large number of diseases that are associated with their dysfunction.