Extended Data Fig. 7: SB-405483 universally potentiates the degradation of PROTAC targets.

(a) Structures and targets of select PROTACs. (b–c) Levels of the indicated protein with SB-405483 with orthosteric ligand relative to orthosteric ligand alone: (b) HEK293T BRD4(BD1)-GFP (c) BRD4(BD2)-GFP. (d) Western blot of CRBN levels after dosing HEK293T cells with OUN20985 with and without SB-405483 for 24 h. (e–f) Western blot of FKBP12 levels after dosing HEK293T cells with (e) dFKBP12-AcN (f) dFKBP12-AcQ with and without SB-405483 for 24 h. (g) Structure of WH-10417-099. (h–j) Volcano plots of HEK293T cells after 24 h incubation with (h) 100 nM WH-10417-099 and 10 µM SB-405483 versus DMSO. (i) 100 nM WH-10417-099 and 10 µM SB-405483 versus 100 nM WH-10417-099. (j) 100 nM WH-10417-099 and 10 µM SB-405483 versus 10 µM SB-405483. (k) Venn diagram analysis of significantly downregulated proteins across comparisons. (l) List of proteins significantly downregulated in global proteomics comparisons. Known targets of WH-10417-099 are in red. Additional kinases are in blue. Previously associated neosubstrates in green. Proteomics were performed with n = 4 biologically independent samples. P-values by t-test (background) method. Data are mean ± s.e and error propagation were performed using the delta method. Flow cytometry data and Western blots are representative of n = 3 biologically independent samples. For uncropped Western blot images, see Supplementary Fig. 6.