Involvement of ATP-dependent pseudomonas exotoxin translocation from a late recycling compartment in the lymphocyte intoxication procedure
摘要
Pseudomonas exotoxin (PE) is a cytotoxin which, after endocytosis, is delivered to the cytosol where it inactivates protein synthesis. Using duaminobenzidine cytochemistry we found over 94%of internalized PE in transferrin (Tf) -positive endosomes of lymphocytes. When PE translocation was examined in a cell-free assay using purified endocytic vesicles more than 40%of endosomal 125I-PE was trnasported after 2 h at 37°C, while a toxin inactivated by a point mutation in its translocation domain was not translocated.