Figure 4. Expression of Myc stabilizes HIF1α protein.

IMECs (vector or Myc-overexpressing) were treated with cycloheximide (CHX) for 20, 40, and 60 minutes. Hypoxic extracts were made by treating cells with 200μM CoCl₂ for 3 hours prior to CHX treatment. Western blot analyses were performed with equivalent amounts of protein using anti-HIF1α, anti-c-Myc, and anti-β-tubulin antibodies. Half-lives of HIF1α and Myc were determined after normalization to β-tubulin. Normoxic HIF1α blots are shown at a longer exposure than the hypoxic HIF1α blots.