PHD2 is one of 4 PHD (PHD1-4) enzymes that function as oxygen sensors and are responsible for the post-translational modification of HIF-1alpha, a component of a transcriptional complex involved in oxygen homeostasis. During normoxic levels, PHDs catalyze the hydroxylation of prolyl residues on HIF-1alpha and target it for proteasomal degradation via the von Hippel-Lindau ubiquitination complex. The PHD isoforms appear to function in a non-redundant manner and may differ in their expression patterns and their catalytic selectivity.
