Fig. 4: SGK1 phosphorylates NLRP3 at serine 5 and inhibits inflammasome formation.
a Co-IP analysis of the serine phosphorylation of NLRP3 from the total lysates of primary mVRML cells of sgk1+/+ or sgk1−/− mice upon stimulation with LPS (200 ng/mL, 3 h) and ATP (5 mM, 30 min). b Co-IP analysis of the serine phosphorylation of NLRP3 from the total lysates of control and SGK1 siRNA-transfected THP-1 cells, which were stimulated with LPS (200 ng/mL, 3 h) and ATP (5 mM, 30 min). c In vitro kinase assay results showing the serine phosphorylation of NLRP3 after incubation with active SGK1-S422D or inactive SGK1-S422A via western blotting analysis. d In vitro kinase assay results showing the serine phosphorylation of wild-type NLRP3 or NLRP3-S5A after incubation with active SGK1-S422D via western blotting analysis. a–d, Protein expression was quantified by gray scanning, n = 3 biologically independent experiments. a, b NLRP3 served as a loading control for western blotting. c, d GST served as a loading control for western blotting. e SDD-AGE assay showing NLRP3 oligomerization in control or SGK1 siRNA-transfected THP-1 cells stimulated with saline, LPS (200 ng/mL, 3 h) or LPS + ATP (5 mM, 30 min). f Co-IP analysis of interaction between GFP-NLRP3 and MYC-ASC in the absence and presence of FLAG-SGK1 in HEK-293T cells stimulation with LPS (200 ng/mL, 3 h) and ATP (5 mM, 30 min). g Co-IP analysis of interaction between NLRP3 and ASC in control or SGK1 siRNA-transfected THP-1 cells, which were stimulated with LPS (200 ng/mL, 3 h) and ATP (5 mM, 30 min). Results are presented as mean ± SD. Statistical analyses were carried out via two-sided t-test for a–d. mVRMLs, mouse vestibular-resident macrophage-like cells; Casp-1 caspase-1. Source data are provided as a Source Data file.
