Figure 1.

Effect of C-terminal deletions on HIF-1α protein expression. 293 cells were transfected with expression vectors encoding HIF-1α constructs and 36 h later were exposed to 20% O₂ or 1% O₂ (hypoxia) for 4 h before nuclear extract preparation. Fifteen-microgram aliquots were fractionated by SDS/PAGE and subjected to immunoblot assay by using an anti-HIF-1α Ab. The constructs analyzed encoded the following residues of HIF-1α: (A) 1–826, 1–754, 1–681, 1–608; and (B) 1–729, 1–726, 1–703. Migration of full-length (FL) and deleted (Δ) forms of HIF-1α are indicated (Right).