Fig. 2: KDM4B activates cGAS–STING signaling through untethering cGAS from chromatin.

A cGAS–STING activity in two individual B16F10 Kdm4b KO and control cells. Cells were treated with HT-DNA (1 μg/ml) for the indicated hours. B Ifnb1 expression in Kdm4b KO and control B16F10 cells. Ifnb1 expression was detected by HT-DNA (1 μg/ml) stimulation for 6 h. C Effects of JIB-04 treatment on cGAS–STING activity in B16F10 and MC38 Kdm4b KO and control cells. Cells were treated with 20 μM JIB-04 for 12 h. HT-DNA (1 μg/ml) or cGAMP (1 μg/ml) were treated for the indicated hours. D cGAS–STING activity in Kdm4b KO or/and Cgas knockout B16F10 cells. Cells were treated with HT-DNA (1 μg/ml) for the indicated hours. E Ifnb1 expression in Kdm4b KO or/and Cgas knockout B16F10 cells. Ifnb1 expression was detected by HT-DNA (1 μg/ml) stimulation for 6 h. F The co-immunoprecipitation of KDM4B and cGAS. The KDM4B with V5-tag was transfected into HEK293T cells with either human or mouse cGAS with HA-tag. Cell lysates were immunoprecipitated using HA antibody and protein A/G agarose beads, and then immunoblotted with the indicated antibodies. G Immunoblot of cGAS in the cytoplasmic, soluble and insoluble nuclear fractions from B16F10 Kdm4b KO cells. Data are mean ± SEM for B and E, one-way ANOVA. *P < 0.05, **P < 0.01.