CASP6 cleaves CASP11 in cell lysates. A, schematic diagram of the cleavage and catalytic sites of caspase-11 (CASP11). p26, p38, and p43 indicate the fragments generated from the potential cleavage sites. B, immunoblot analysis of pro- (p43) and cleaved CASP11 (p38 and p26), caspase-8 (CASP8), caspase-9 (CASP9), caspase-12 (CASP12), caspase-1 (CASP1), caspase-7 (CASP7), caspase-6 (CASP6), and caspase-3 (CASP3) in 293T cells transfected with the indicated expression plasmids. Actin was used as the internal control. C, immunoblot analysis of pro- and cleaved CASP11 and CASP6 in 293T cells transfected with the indicated expression plasmids. Actin was used as the internal control. D, immunoblot analysis of pro- and cleaved CASP11 and CASP6 in 293T cells transfected with the indicated expression plasmids. Actin was used as the internal control. The data are representative of at least three independent experiments. CARD, caspase-activation and recruitment domain; CASP, caspase.