Fig. 3. Onco endocytosis and toxicity are regulated by Rab5. (A) Onco internalization depends on Rab5. Jurkat cells were transfected with the indicated Rab5 or Rab7 expression vectors, together with EGFP. After 24 hours, Onco-Red and Tf-Cy5 were added for 45 minutes before fixation and confocal microscopic examination. Bar, 10 µm. (B) Cellubrevin and Rab5 regulate Onco delivery to the cytosol. Jurkat cells were transfected with EGFP and either the wild type or a mutated version of Rab5, Rab7 or TeNT-LC, as indicated. After 24 hours, 6 µM Onco was added. Cytotoxicity was measured after 24 hours, on transfected cells, using annexin-V-Cy5 labeling and FACS analysis.