SGT1 and HSP90 bind the NLRP3 (NALP3) LRR domain.
Genetic studies in plants suggest a role for SGT1-HSP90 as co-chaperones of plant resistance (R) proteins, serving to maintain them in an inactive but signaling-competent state. R-protein activation is beleived to lead to dissociation of the SGT1-HSP90 complex. SGT1 and HSP90 are highly conserved, while R proteins are structurally related to mammalian NLRs.
Human SGT1 and HSP90 were found to bind NLRP3 (Mayor et al. 2007). Knockdown of human SGT1 by small interfering RNA or chemical inhibition of HSP90 by geldanamycin abrogated NLRP3 inflammasome activity in human monocytic cell line THP-1 (Mayor et al. 2007). Similarly, NLRP3 inflammasome activation was abrogated in geldanamycin-treated human retinal pigment epithelial (RPE) cells (Piippo N et al. 2018). These data indicate that SGT1 and HSP90 are involved in regulation of NLRP3 inflammasome signaling (Mayor et al. 2007; Piippo N et al. 2018).
De Smedt, T,