Open AccessEvolution-inspired redesign of the LPS receptor caspase-4 into an interleukin-1β–converting enzyme
Author(s) -
Pascal Devant,
Anh Cao,
Jonathan C. Kagan
Publication year - 2021
Publication title -
science immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.83
H-Index - 51
ISSN - 2470-9468
DOI - 10.1126/sciimmunol.abh3567
Subject(s) - caspase , inflammasome , innate immune system , microbiology and biotechnology , biology , caspase 1 , signal transduction , inflammation , nlrp1 , apoptosis , immune system , immunology , biochemistry , programmed cell death
Innate immune signaling pathways comprise multiple proteins that promote inflammation. This multistep means of information transfer suggests that complexity is a prerequisite for pathway design. Herein, we test this hypothesis by studying caspases that regulate inflammasome-dependent inflammation. Several caspases differ in their ability to recognize bacterial LPS and cleave interleukin-1β (IL-1β). No caspase is known to contain both activities, yet distinct caspases with complementary activities bookend an LPS-induced pathway to IL-1β cleavage. Using caspase-1/4 hybrid proteins present in canines as a guide, we identified molecular determinants of IL-1β cleavage specificity within caspase-1. This knowledge enabled the redesign of human caspase-4 to operate as a one-protein signaling pathway, which intrinsically links LPS detection to IL-1β cleavage and release, independent of inflammasomes. We identified caspase-4 homologues in multiple carnivorans which display the activities of redesigned human caspase-4. These findings illustrate natural signaling pathway diversity and highlight how multistep innate immune pathways can be condensed into a single protein.