Fig. 1 |. G3BP1 is critical for cGAS-mediated type I interferon production.

a, Representative immunoblot (IB) of wild-type (WT) and G3BP1^−/− U937 cells with indicated antibodies. b,c, qPCR analysis of IFNB mRNA expression in U937 cells transfected with HT-DNA (2 μg ml⁻¹) (b) or plasmid DNA (2 μg ml⁻¹) (c) for indicated time. d, qPCR analysis of IFNB mRNA expression in U937 cells transfected with DNA of different length (2 μg ml⁻¹) (n = 2 independent experiments). e,f, qPCR analysis of Ifnb mRNA expression in WT and G3bp1^−/− MEFs transfected with HT-DNA (0.5 μg ml⁻¹) (e) or plasmid DNA (0.5 μg ml⁻¹) (f) for indicated time. g,j, Immunoblot analysis of U937 cells treated with HT-DNA (g) or cGAMP (1 μg ml⁻¹) (j). h, cGAMP production of HT-DNA-treated WT or G3BP1^−/− U937 cells was analyzed by LC–MS/MRM. ND, not detected. i, qPCR analysis of IFNB mRNA expression in cGAMP-treated U937 cells. k,l, ELISA of secreted IFN-β (k) and qPCR analysis of HSV-1 RNA (l) in U937 cells that were untreated (−) or infected with HSV-1 (multiplicity of infection = 1) (+) for 24 h. β-Actin, loading control (a,g,j). *P < 0.05, **P < 0.01, ***P < 0.001, two-tailed t-test (b,c,e,f,h,k,l). Data are representative of three experiments (a–c,e–l). Data are mean ± s.e.m. of triplicate samples in b,c,e,f,h,i,k,l. U937 cells were differentiated with PMA (phorbol 12-myristate 13-acetate) before any treatment, unless stated otherwise.