FIG. 7.

HIF-1-dependent induction of c-Jun N-terminal phosphorylation and c-jun expression in cocultured wt and HIF-1α-null cells exposed to hypoxia or anoxia. (A) Immunoblot of total protein harvested from mEFs in the wells of modified Boyden chambers after exposure to normoxic conditions (air-5% CO₂) or hypoxia (pO₂, ≤0.01%; 8 h). wt and HIF-1α-null mEFs were plated on either cell-impermeant inserts or companion wells of the chambers and were cocultured in the same medium before and during exposure to hypoxia. The blot was probed with the anti-phospho-c-Jun antibody KM-1 (P-c-Jun). (B) Histogram of relative amounts of c-jun mRNA detected by quantitative RT-PCR amplification of total RNA harvested from mEFs in the wells of modified Boyden chambers after exposure to normoxic conditions (air-5% CO₂) or hypoxia (pO₂, ≤0.01%; 8 h). Open bars (same), identical genotypes in the chamber or insert; shaded bars (mixed), different genotypes in the chamber or insert. Error bars, sample standard deviations for triplicate measurements. For details, see Materials and Methods.