Egl nine homolog 2 (EGLN2)

Cellular oxygen sensor that catalyzes, under normoxic conditions, the post-translational formation of 4-hydroxyproline in hypoxia-inducible factor (HIF) alpha proteins. Hydroxylates a specific proline found in each of the oxygen-dependent degradation (ODD) domains (N-terminal, NODD, and C-terminal, CODD) of HIF1A.

Has a preference for the CODD website for both HIF1A and HIF2A. Under hypoxic conditions, the hydroxylation reaction is attenuated allowing HIFs to escape degradation resulting in their translocation into the nucleus, heterodimerization with HIF1B, and increased expression of hypoxy-inducible genes.