Characterization of tBid-induced cytochrome c release from mitochondria and liposomes

tBid, the cleaved form of Bid, can induce cytochrome c (Cyt, c) release fro m rat heart mitochondria more efficiently and reproducibly than that from l iver or brain mitochondria, Unlike Bas, such release was not prevented by c yclosphorin A, an inhibitor of the opening of permeability transition pore. Carbonyl-cyanide m-chlorophenyl-hydrazone or oligomycin also have no obvio us effect on the release of Cyt. c, In contrast to ceramide, tBid-mediated Cyt. c release from mitochondria is independent of the redox state of Cyt. c. Furthermore, Bid or tBid can directly trigger the efflux of encapsulated Cyt, c or trypsin within liposomes without involvement of other protein fa ctors. (C) 2000 Federation of European Biochemical Societies.