SUMO1 SUMOylates and SENP3 deSUMOylates NLRP3 to orchestrate the inflammasome activation

Abstract

contributed equally to this work.Abbreviations: AIM2, absent in melanoma 2; ASC, apoptosis-associated speck-like protein containing a caspase recruitment domain; BMDM, bone marrow-derived macrophage; Casp-1, caspase-1; FITC, fluorescein isothiocyanate; GAPDH, glyceraldehyde 3-phosphate; HEK293T, human embryonic kidney cell line; IL-1β, interleukin-1β; LDH, lactate dehydrogenase; LRR, leucine-rich repeat; NACHT, NAIP (neuronal apoptosis inhibitory protein), CIITA (MHC class II transcription activator), HET-E (incompatibility locus protein from Podospora anserina) and TP1 (telomerase-associated protein); NLRP3, NACHT, LRR, and PYD domains-containing protein 3; PYD, pyrin domain; SENP, SUMO-specific protease; shRNA, short hairpin RNA; SUMO, small ubiquitin-like modifier; TCA, trichloroacetic acid solution; THP-1, human monocytic cell line; TPA, phorbol-12-myristate-13-acetate; UBC9, ubiquitin-like conjugating enzyme 9. AbstractThe NLRP3 inflammasome regulates innate immune and inflammatory responses by promoting caspase1-dependent induction of pro-inflammatory cytokines. However, aberrant inflammasome activation causes diverse diseases, and thus inflammasome activity must be tightly controlled. Here, we reveal a molecular mechanism underlying the regulation of NLRP3 inflammasome. NLRP3 interacts with SUMO-conjugating enzyme (UBC9), which subsequently promotes small ubiquitin-like modifier 1 (SUMO1) to catalyze NLRP3 SUMOylation at residue Lys 204 . SUMO1-catalyzed SUMOylation of NLRP3 facilitates ASC oligomerization, inflammasome activation, and interleukin-1β secretion. Moreover, this study also reveals that SUMO-specific protease 3 (SENP3) is required for the deSUMOylation of NLRP3. Interestingly, SENP3 deSUMOylates NLRP3 to attenuate ASC recruitment and speck formation, the NLRP3 inflammasome activation, as well as IL-1β cleavage and secretion. In conclusion, we reveal that SUMO1-catalyzed SUMOylation and SENP3-mediated deSUMOylation of NLRP3 orchestrate the inflammasome activation. K E Y W O R D Sinflammasome, innate immune response, interleukin-1β, posttranslational modification, SUMO1catalyzed SUMOylation 1498 | SHAO et Al.

The ubiquitylation of IL-1β limits its cleavage by caspase-1 and targets it for proteasomal degradation

“…The post-translational regulation of the inflammasome machinery has received substantial attention in recent years, including ubiquitylation, SUMOylation, and phosphorylation of inflammasome sensor proteins, such as NLRP3, as well as the inflammasome adapter ASC and caspase-1 [37][38][39][40][41] . Our TUBE purification and analysis of ubiquitylated inflammasome components suggest that only NLRP3 and IL-1β are robustly decorated by ubiquitin chains upon TLR-mediated inflammasome priming.…”

Regulation of the NLRP3 Inflammasome by Post-Translational Modifications and Small Molecules

“…Deficiency of sentrin-specific protease 6 (SENP6) and SENP7, which are SUMO de-conjugating enzymes, reduced NLRP3 inflammasome activation ( 87 ). In contrast, SUMO1-catalyzed sumoylation of NLRP3 Lys204 promoted inflammasome activation whereas SENP3, a deSUMOylase, induced NLRP3 deSUMOylation to attenuate inflammasome activation ( 88 ). The precise role of sumoylation by different enzymes and at different activation steps needs to be further elucidated.…”

An update on the regulatory mechanisms of NLRP3 inflammasome activation

“…However, another study showed that SUMOylation of NLRP3 at K204 by SUMO1 facilitates ASC oligomerization and NLRP3 inflammasome activation. 68 Additional studies are needed to understand how multiple PTM pathways are selected and coordinated for the priming/licensing of NLRP3 and its oligomerization.…”