Pfanner, Nikolaus; Hoeben, Peter; Tropschug, Maximilian; Neupert, Walter
(5. November 1987):
The carboxyl-terminal two-thirds of the ADP/ATP carrier polypeptide contains sufficient information to direct translocation into mitochondria.
In: The Journal of Biological Chemistry, Vol. 262, No. 31: pp. 14851-14854
The precursor of the mitochondrial inner membrane protein ADP/ATP carrier is cytoplasmically synthesized without an amino-terminal peptide extension. We constructed a truncated precursor lacking the 103 amino acids from the amino terminus (about a third of the protein). Import of the truncated precursor into mitochondria showed the import characteristics of the authentic precursor, including nucleoside triphosphate dependence, requirement for a protease-sensitive component on the mitochondrial surface, two-step specific binding to the outer membrane, and membrane potential-dependent translocation into the inner membrane. We conclude that, in contrast to all other mitochondrial precursor proteins studied so far, domains of the ADP/ATP carrier distant from the amino terminus can carry specific targeting information for transport into mitochondria.