Figure 2.

Hypoxia induces G₁ arrest in MEF^WT but not in MEF^PERK-/-, MEF^GCN2-/-, and MEF^A/A cells. (A) The cells were treated with hypoxia for 12 hours before the cell cycle analysis using flow cytometry. The data were analyzed by ModFit software. The bars represent the means of three independent experiments. *P < .05 hypoxia versus normoxia. (B) The cells were treated with hypoxia for the time points as indicated, and the protein levels of HIF-1α and p21^WAF1 were analyzed by Western blot.