FIG. 2.
Combined p38 MAP kinase and JNK activation in pX-mediated apoptosis. (A) Transient-transfection trans-reporter assays employing the pFR luciferase reporter (100 ng) cotransfected with the pFA-c-Jun (100 ng) or pFA-Chop-10 (100 ng) expression vectors (Stratagene) in apoptotic 4pX-1 cultures, which were grown in the presence or absence of 5 μg of tetracycline per ml. Results are from three independent assays performed in triplicate. (B) Western blot analyses of phospho-p38 MAP kinase and phospho-JNK using apoptotic 4pX-1 whole-cell extracts isolated at the indicated times as a function of pX expression. The results of a representative assay from three independent experiments are shown. (C) Radioactive DNA fragmentation assays of DNA isolated from apoptotic 4pX-1 cultures in the presence or absence of 5 μM SB 202190 or in the presence or absence of 5 μM SP 600125. (D) Quantification of results of radioactive DNA fragmentation assays performed with ImageQuant (version 5.0; Molecular Dynamics). Results are representative of three independent assays (P < 0.01).