Figure 2. STING variants are responsive to cGAS.

(A) HEK293T cells were transfected with the indicated STING alleles and with human and mouse cGAS (wt and GS>AA mutants) (Sun et al., 2013) as indicated. STING activation was assessed by a co-transfected IFN-luciferase reporter construct. (B) HEK293T cells were transfected with the indicated STING alleles and with a mammalian expression vector encoding a cGAMP synthase (DncV) from V. cholerae. STING activation was assessed as in A. (C) In vitro enzymatically generated products of rWspR, rDncV and rcGAS were transfected into digitonin permeabilized HEK293T cells expressing the indicated mouse and human STING proteins. Chemically synthesized cyclic-di-GMP (cdG) and cGAMP were included as controls. STING activation was assessed as in A and B. Data are representative of at least three independent experiments and are presented as mean. Error is represented as standard error of the mean. See also Figure S2.