Biochem/physiol Actions

Originally characterized an ATP site-targeing kinase inhibitor (IC50 in nM = 2/VEGFR2, 15/SRC, 47/C-FMS, 851/GSK3, 9016/ERBB2, 9120/FGFR) with potent antiproliferation activity against cancer cultures (IC50 in nM = 5/HUVEC-v, 424/HUVEC-b, 81/HEF, 453/MDA468, 470/A375P, 693/HT29, 734/PC3), GW806742X is now better known as Compound 1 for its anti-necroptosis activity via affinity interaction with MLKL pseudokinase domain (Kd = 9.3 µM), thereby preventing the 4HB domain from exerting its necroptototic effect following RIPK3-mediated pseudokinase domain phosphorylation. GW806742X inhibits TSQ (1 ng/mL TNF, 500 nM Smac-mimetic, 10 µM Q-VD-Oph) treatment-induced necroptosis of mouse dermal fibroblasts (IC50 ﹤50 nM) with >50-fold greater potency than Nec-1, while reduced efficiency is only observed in the presence of supraphysiological TNF concentrations of 100 ng/mL (IC50 = 100-500 nM; Max efficacy ~50%).