Fig. 4: Structural basis for phospho-regulation of STING recognition by AP-1.
From: Clathrin-associated AP-1 controls termination of STING signalling
a, Three-dimensional (3D) reconstructions of the complex in two different orientations. The atomic models of dimeric human LBD-STING (Protein Data Bank (PDB) code: 4KSY) and the AP-1 complex (PDB 6DFF) were fitted into the maps (grey) through rigid-body docking. b, High-resolution 3D reconstruction from focused refinement on the AP-1 core and pSTING tail at 2.34-Å resolution contoured at 3σ. c, Ribbon representation of the AP-1 pSTING complex structure. d–f, Detailed views of the binding interface. e, Potentialhydrophobic interactions around the EXXXLI motif are indicated with dotted lines. The density map (grey mesh) of pSTING tail is contoured at 3σ. f, Potential hydrogen bonds around pS366 indicated with dotted lines. The density map (grey mesh) of the pSTING tail is contoured at 3σ. g, HEK293T cells transfected with Flag-tagged STING and HA-tagged wild-type AP-1σ or AP-1σ mutants σKR (K60A/R61A), σ(I103S) and σ(V88D) were stimulated with diABZI for 2 h. Cell lysates were extracted, immunoprecipitated with anti-Flag antibody and analysed by western blot. h, WCL and CCV fractions from untreated and diABZI-treated HeLa STING KO cells reconstituted with Flag-tagged wild-type STING and the indicated STING mutants STINGLI, STINGLR(L374A/R375A) or STING(S358A) were analysed by western blot. CHC and GAPDH were used as loading controls. i, HeLa STING KO cells reconstituted with Flag-tagged STING and the indicated STING mutants STING(S358A), STING(S366A) or STING(S358/366A) were stimulated with diABZI for 2 h or left untreated. After immunoprecipitation with anti-Flag antibody, samples were analysed by western blot. j, Schematic diagram of the function of AP-1 in the termination of STING signalling. One representative example of at least three (g–i) independent experiments is shown.
