Fig. 2.

Hypoxia sensitivity of the FIH-dependent FIH-OTUB1 heterodimer formation. (A) Heterodimer (HD) formation was sensitive to hypoxia (Hx, 0.2% O₂), DMOG and DFX, but not to the PHD-specific inhibitor FG-4592. (B) Immunoblotting of cell lysates with the indicated ectopic expressions. The H199A FIH mutant is catalytically inactive and was incapable of forming the HD. (C) Hypoxia sensitivity of HD formation in comparison with HIF-1α and HIF-2α stabilization following 24 h of incubation at the indicated O₂ levels. (D) Quantification of the experiment described in (C) and calculation of the oxygen sensitivity of HD formation and HIF-1α and HIF-2α stabilization based on this quantification. Nx, normoxia; M, monomer. Data are shown as mean ± SEM from four independent experiments or are representative for (A, B) three or (C) four independent experiments.