FIG 10.

Model for activation of transcription from Zp via p53/HIF complexes. Neither phosphorylated HIF-1α/β nor p53 by itself can activate transcription from Zp (A and B, respectively). Rather, phosphorylated p53 binds indirectly to Zp via HIF-1α/β HIF-1α/β (model C) or directly to Zp, with its binding stabilized via interaction with HIF-1α/β (model D). Other coactivators, such as p300/CBP, may also be present in the p53/HIF-1α/β complex, further stabilizing the direct or indirect binding of p53 to Zp (model E or F, respectively).