Adenine nucleotide translocator
Adenine nucleotide translocator (ANT), also known as the ADP/ ATP translocator, exports ATP from the mitochondrial matrix and imports ADP into the matrix. ANT is the most plentiful protein in the inner mitochondrial membrane.
FunctionANT 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 as a monomer in detergents and in mitochondrial membranes. ANT is an important structural component of the mitochondrial permeability transition pore which can open and lead to cell death through apoptosis or necrosis.
TypesIn humans, there exist three paraologous ANT isoforms:
- SLC25A4 – found primarily in heart and skeletal muscle
- SLC25A5 – primarily expressed in fibroblasts
- SLC25A6 – primarily express in liver