In silico investigation of PHD-3 specific HIF1-α proline 567 hydroxylation: A new player in the VHL/HIF-1α interaction pathway?

Hypoxia inducible factor 1α (HIF-1α) regulates oxygen homeostasis in the cell through a sensing mechanism involving its hydroxylation and binding to the von Hippel-Lindau (VHL) tumor suppressor. This mechanism is mediated through hydroxylation of HIF-1α proline 564, although in vitro tests have previously shown an alternative hydroxylation at proline 567 by PHD-3. Here, molecular dynamics simulations were used to investigate the structural effect of this alternative hydroxylation. A specific hydrogen bond network rearrangement and improved electrostatic energy for hydroxylated P567 are compatible with an increase in HIF-1α binding affinity. Sequence analysis also confirms P567 to be vastly conserved during evolution, indicating a possible role for this alternative, PHD-3 driven, post translational modification in pVHL-HIF-1α complex formation.