Figure 5.

Autoprocessing of 43-kD caspase-11 in vitro. A, Cleavage of caspase-11 in vitro. 1 μl of ³⁵S-labeled caspase-11, in vitro translated from its full-length cDNA (pS15), was mixed with 1 μg of purified procaspase-11 (pS15) in a total volume of 10 μl. The mixtures were incubated at 37°C for the time indicated at the top of the panel. The cleavage products of labeled procaspase-11 by procaspase-11 enzyme were analyzed by SDS-PAGE and autoradiography. B, Cleavage of caspase-11 in apoptosis. L929 cells were incubated with indicated amounts of etoposide overnight, which induced 50–80% of cells to die and the cleavage of caspase-11 was determined by Western blot using anticaspase-11 (17D9).