Figure 4.

Phosphoglycerate kinase 1 (PGK1) interacts with hypoxia‐inducible factor (HIF)‐2α and mediates ATP‐induced HIF‐2α elevation. A, MCF‐7 cells were treated with/without ATP for 24 h. Cells were lysed and co–immunoprecipitated with anti–immunoglobulin G (IgG) or anti–HIF‐2α. The elutes were resolved by SDS‐PAGE, silver‐stained. The presence of PGK1 was detected by mass spectrometry. B, Physical interaction between PGK1 and HIF‐2α was determined by co–immunoprecipitation and western blotting. C, Cells were double‐stained with HIF‐2α (green) and PGK1 (red) and counterstained with DAPI (blue). The merged regions indicated their co–localization. D, Western blotting demonstrated that PGK1‐siRNA abolished ATP‐driven upregulation of HIF‐2α but did not affect HIF‐1α expression