Figure 5.

Pathway model of inflammatory caspase functions. Based on the k_cat/K_m values presented in this paper, caspase-11 is unlikely to be involved in directly processing pro-interleukins, as emphasized by the relative weights of the arrowed lines. However, monocytic cells treated with non-canonical stimuli that activate caspase-11 still retain the ability to process the pro-interleukins. As discussed in the text, there cannot be a direct activation of caspase-1 by caspase-11, so there must be an intermediate factor(s) that respond to active caspase-11 by ultimately activating caspase-1, most likely via the canonical pathway. In contrast, both caspases are able to directly activate GSDMD in a timely manner to generate pyroptosis.