Figure 1.

Canonical innate immune pathways induced by DNA. DNA from multiple sources induces the dimerization of cGAS and facilitates cGAS to catalyze the synthesis of cGAMP using ATP and GTP. cGAMP binds with STING and activates STING on the ER membrane. STING then activates TAK1, which directly mediates the phosphorylation of STING at S355 in a TAB1-dependent manner, facilitating the interaction between STING and STEEP. The interaction promotes STING oligomerization and translocation from ER to GA via ERGIC, recruiting and activating TBK1 and IKK complex. Activated TBK1 and IKK phosphorylate IRF3 and NF-κB, respectively, and promote the nuclear translocation of IRF3 and NF-κB, thereby inducing the expression of cytokines including type I IFN. The figures were created using scientific image and illustration software, BioRender (BioRender.com).