The innate immunity constitutes an efficient barrier by rapidly detecting pathogens and tissue damages through pattern recognition receptors including NLRP3. On the other hand, inappropriate NLRP3 activation causes deleterious inflammation and contributes to various conditions including atherosclerosis, diabetes, gout and Alzheimer's diseases. Therefore NLRP3 requires tight regulation that remains poorly characterized. Activated NLRP3 assembles a multimeric inflammasome complex serving as activation platform for caspase-1 that controls processing and release of cytosolic cytokines including IL-1β. We recently evidenced that inflammasome assembly requires NLRP3 deubiquitination by the deubiquitinase BRCC3. The aim of this proposal is to decipher this new ubiquitin-dependent regulatory pathway critical for NLRP3 activation. We propose to identify stimuli, signaling pathways and enzymatic complexes controlling NLRP3 ubiquitination level. Using both cell biology and biochemistry approaches, we will decipher the molecular mechanisms beneath the regulation of the deubiquitinase and ubiquitin ligase complex activity, as well as the loss of activity of ubiquitinated NLRP3. Lastly, we will test the in vivo relevance of NLRP3 ubiquitination using both mouse models, patients study and pharmacological approach. Altogether, this project will thoroughly characterize this new pathway controlling inflammasome activity and provide new therapeutic targets against inflammation related diseases that are highly prevalent in the European Union.