Adenine nucleotide translocator

Adenine nucleotide translocator (ANT) also known as the ADP/ATP translocator is a mitochondrial protein.

Function
ANT has long been thought to function asymmetrically as a homodimer of subunits in the inner mitochondrial membrane. The dimer was thought to be a gated pore through which ADP and ATP were exchanged between the mitochondrial matrix and the cytoplasm. The dimer hypothesis was first challenged when the three-dimensional structure of ANT was discovered to be a monomer. Further work has shown that ANT functions a monomer in detergents and in mitochondrial membranes.

Types
In humans, there exist three paraologous ANT isoforms:
 * SLC25A4 – found primarily in heart and skeletal muscle
 * – primarily expressed in fibroblasts
 * SLC25A6 – primarily express in liver