NEK7 Cys298 is important for NLRP3 inflammasome and targetable by dimethyl fumarate.

Dimethyl fumarate (DMF), a cysteine targeting agent, is clinically used to treat multiple sclerosis and psoriasis. However, its precise molecular mechanism remains incompletely understood. Here, we investigated the effects of DMF on NLRP3 inflammasome activation. DMF suppresses NLRP3 inflammasome activity at both the priming and activation steps. Using chemoproteomics, we identified DMF targets in macrophages, including IRAK3/4 and RELA/B involved in the NLRP3 priming step, NEK7 involved in NLRP3 early activation, and GSDMD involved in NLRP3 late activation. To understand how DMF inhibits NLRP3 early activation, we showed that DMF modifies NEK7 Cys298 to disrupt NLRP3-NEK7 interaction and inflammasome activation. Interestingly, NEK7 Cys298 is critical for NLRP3 inflammasome activation. This study provides mechanistic insights into DMF's immunomodulatory effects and suggests that targeting NEK7 Cys298 can be a novel strategy for inflammatory diseases. Our work highlights the utility of DMF to identify functionally important cysteine residues in immune signaling pathways.