title: Transport of ADP/ATP carrier into mitochondria. Precursor imported in vitro acquires functional properties of the mature protein.
abstract: Precursor to ADP/ATP carrier synthesized in vitro is transferred into isolated mitochondria to a protease-resistant location. This process requires an electrical potential across the inner membrane. We show now that precursor imported in a cell-free system exhibits the same resistance to protease as the mature endogenous carrier. Furthermore, transferred protein, but not receptor-associated precursor, binds carboxy-atractyloside, a specific inhibitor of the mature carrier and can be isolated by the purification procedure for the mature carrier. At least 70% of the precursor associated with mitochondria in the presence of a membrane potential acquires this functional characteristic. Finally, the binding of carboxyatractyloside can be modulated by treatment of the imported protein with sulfhydryl reagents in a manner indistinguishable from the authentic carrier protein. We conclude that import in vitro leads to correct assembly and orientation of the ADP/ATP carrier in the mitochondria.
mesh_terms: D000818:Animals; D005033:Ethylmaleimide / Q000494:pharmacology; D007425:Intracellular Membranes / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D009491:Neurospora / Q000378:metabolism*; D009492:Neurospora crassa / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism*; D014176:Protein Biosynthesis; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear; D012156:Reticulocytes / Q000378:metabolism; D014634:Valinomycin / Q000494:pharmacology
chemical_list: C037688:ADP-ATP carrier receptor; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D014634:Valinomycin; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; D005033:Ethylmaleimide