FIG. 10.

Enhancement of the anti-Fas signal by DNP occurs in the absence of detectable cytochrome c redistribution. (a) Jurkat cells (4 × 10⁷/sample) were treated with the agents indicated as described above. After 2 h, cells were collected by centrifugation and homogenized as described in Materials and Methods. Supernatants (containing cytosol and light membranes) and pellets (containing mitochondria) from the 10,000 × g centrifugation step were separated by SDS-PAGE and analyzed by Western blotting. Separate blots were probed with MAb to cytochrome oxidase subunit I (COX, top) and cytochrome c (bottom). These results are representative of five independent experiments. (b) Jurkat cells (2 × 10⁷/sample) were treated for 2.5 h as indicated (fas/DNP, anti-Fas MAb [100 ng/ml] and DNP [1 mM]; stauro, staurosporine [1 μM]). Fractions were prepared and analyzed as described above.