IL-1β turnover by TRIP12 and AREL1 ubiquitin ligases and UBE2L3 limits inflammation

Mishra, V.; Crespo-Puig, A.; McCarthy, C.; Masonou, T.; Glegola-Madejska, I.; Dejoux, A.; Dow, G.; Eldridge, M. J. G.; Marinelli, L. H.; Meng, M.; Wang, S.; Bennison, D. J.; Shenoy, A. R.

doi:10.1101/2022.09.14.507790

bioRxiv · 10.1101/2022.09.14.507790

IL-1β turnover by TRIP12 and AREL1 ubiquitin ligases and UBE2L3 limits inflammation

Mishra, V.·Crespo-Puig, A.·McCarthy, C.·Masonou, T.·Glegola-Madejska, I.·Dejoux, A.·Dow, G.·Eldridge, M. J. G.·Marinelli, L. H.·Meng, M.·Wang, S.·Bennison, D. J.·Shenoy, A. R.

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Abstract

The cytokine interleukin-1{beta} (IL-1{beta}) has pivotal roles in antimicrobial immunity, but also incites inflammatory pathology. Bioactive IL-1{beta} is released following proteolytic maturation of the pro-IL-1{beta} precursor by caspase-1 inflammasomes. UBE2L3/UBCH7, a conserved ubiquitin conjugating enzyme, promotes pro-IL-1{beta} ubiquitylation and proteasomal disposal. However, UBE2L3 actions in vivo and ubiquitin ligases involved in this process are unknown. Here we report that deletion of Ube2l3 in mice markedly reduces pro-IL-1{beta} turnover in macrophages, leading to excessive mature IL-1{beta} production, neutrophilic inflammation and disease symptoms following inflammasome activation. A family-wide siRNA screen identified two ubiquitin ligases, TRIP12 and AREL1, which we show add K27-, K29- and K33- poly-ubiquitin chains on lysine residues in the pro domain and destabilise pro-IL-1{beta}. Mutation of ubiquitylation sites increased pro-IL-1{beta} stability, but did not affect proteolysis by caspase-1. The extent of mature IL-1{beta} production is therefore determined by precursor abundance, and UBE2L3, TRIP12 and AREL1 limit inflammation by shrinking the cellular pool of pro-IL-1{beta}. Our study has uncovered fundamental processes governing IL-1{beta} homeostasis and provided molecular insights that could be exploited to mitigate its adverse actions in disease.

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Mishra, V., Crespo-Puig, A., McCarthy, C., Masonou, T., Glegola-Madejska, I., Dejoux, A., Dow, G., Eldridge, M. J. G., Marinelli, L. H., Meng, M., Wang, S., Bennison, D. J., Shenoy, A. R.. 2022-09-14. IL-1β turnover by TRIP12 and AREL1 ubiquitin ligases and UBE2L3 limits inflammation. https://doi.org/10.1101/2022.09.14.507790

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