The translocator protein (peripheral benzodiazepine receptor) mediates rat-selective activation of the mitochondrial permeability transition by norbormide

►The permeability transition pore (PTP) is an inner membrane mitochondrial channel. ►The rat-selective toxicant norbormide (NRB) is species-selective for PTP opening. ►The PTP-inducing effect is lost in mitoplasts (devoid of the outer membrane). ►NRB transport depends on the outer membrane protein TSPO. ►We have tentatively identified the TSPO residues responsible for transport of NRB.