Data for: ASC oligomer favors caspase-1 CARD domain recruitment after intracellular potassium efflux

Signaling through the inflammasome is important for the inflammatory
response. Low concentrations of intracellular K+are associated with the
specific oligomerization and activation of the NLRP3 inflammasome, a type
of inflammasome involved in sterile inflammation. After NLRP3
oligomerization, ASC protein binds and forms oligomeric filaments that
culminate in large protein complexes named ASC specks. ASC specks are also
initiated from different inflammasome scaffolds, such as AIM2, NLRC4 or
Pyrin. ASC oligomers recruit caspase-1 and then induce its activation
through interactions between their respective caspase activation and
recruitment domains (CARD). So far ASC oligomerization and caspase-1
activation are K+-independent processes. Here we found that, when there is
low intracellular K+, ASC oligomers change their structure independently
of NLRP3 and make the ASCCARD domain more accessible for the recruitment
of the pro-caspase-1CARD domain. Therefore, conditions that decrease
intracellular K+ not only drive NLRP3 responses but also enhance the
recruitment of pro-caspase-1 CARD domain into the ASC specks.