The SUMOylation of proteins alters their activity, stability and cellular distribution49–51. SUMO has been implicated in the development of Amyotrophic Lateral Sclerosis and Huntington’s and Parkinson’s diseases52,53, in which the accumulation of fibrillar proteins is a proposed aetiology. There are parallels between amyloidosis and the assembly of immune cell signalling complexes. We speculate that the modification of ASC that we have identified may function as has been identified for the Mitochondrial antiviral signalling (MAVS) protein. In this instance, viral infection induces the formation of a prion-like aggregate of MAVS that is also controlled by its modification with SUMO54. Rather than directly promoting MAVS aggregation, it is proposed that SUMOylation promotes the recruitment of signalling components. As SUMO1 appears dispensable for inflammasome assembly, we speculate that ASC SUMOylation isn’t directly recruiting protein partners but is partitioning ASC within the cytosol to promote the assembly of inflammasomes (Fig. 9).
