Fig. 4: OTUB1 interacts with HIF-1α.

A, B Co-immunoprecipitation of Flag-OTUB1 with Myc-HIF-1α and vice versa. HEK293T cells were co-transfected with indicated plasmids and cultured under normoxia (21% O₂) for 24 h. Anti-Flag (A) or anti-Myc antibody-conjugated agarose beads (B) were used for immunoprecipitation, and the interaction was detected by immunoblotting with the indicated antibodies. C Endogenous interaction between OTUB1 and HIF-1α. HEK293T cells were cultured under hypoxia (1% O₂) for 4 h. Anti-HIF-1α antibody was used for immunoprecipitation, and normal rabbit IgG was used as a control. D Schematic of HIF-1α domains interacted with OTUB1. The interaction is indicated by plus (+) sign. E Co-immunoprecipitation analysis of Flag-OTUB1 with Myc-HIF-1α-truncated mutants. HEK293T cells were co-transfected with the indicated plasmids and cultured under normoxia (21% O₂) for 24 h. Anti-Myc antibody-conjugated agarose beads were used for immunoprecipitation, and the interaction was analyzed by immunoblotting with the indicated antibodies. Myc-HIF-1α fragments (HIF-1α-N1, 1–80 aa; HIF-1α-N2, 1–200 aa; HIF-1α-N3, 1–330 aa; HIF-1α-N4, 1–399 aa; HIF-1α-N5, 1–575 aa; HIF-1α-N6, 1–785 aa). F Schematic of OTUB1 domains interacted with HIF-1α. The interaction is indicated by plus (+) sign. G Co-immunoprecipitation analysis of Myc-HIF-1α with Flag-OTUB1-truncated mutants. HEK293T cells were co-transfected with the indicated plasmids and cultured under normoxia (21% O₂) for 24 h. Anti-Flag antibody-conjugated agarose beads were used for immunoprecipitation, and the interaction was analyzed by immunoblotting with the indicated antibodies. Flag-OTUB1 fragments (OTUB1-N, 1–80 aa; OTUB1-C, 81–271 aa).