FIG. 1.

Apoptosis-induced cleavage of hRad21 in Molt4 T-cell leukemia and JEG3 choriocarcinoma cells treated with etoposide, prostaglandin, and proteasome inhibitors. (A) Dose-related cleavage of hRad21 in Molt4 T-cell leukemia cells treated with increasing concentrations of etoposide (10 to 50 μM) for 6 h. (B) JEG3 cells treated with 15DPGJ₂ (2.4 to 8 μM) for 16 h. (C) Molt4 cells were also treated with a 0.025 mM concentration of proteasome inhibitors, MG115, and MG132 for 8 h. Lysates of these samples were resolved on an SDS-PAGE (4 to 20% acrylamide) gel, transferred to a nitrocellulose membrane, and analyzed by Western blot using a monoclonal hRad21 antibody. Induction of apoptosis resulted in the generation of approximately 64- and 60-kDa hRad21 cleavage products (shown by the closed arrows). Full-length hRad21 (122 kDa) is indicated by the open arrow.