HIF-1 and HIF-2: working alone or together in hypoxia?
J. Clin. Invest. Peter J. Ratcliffe, et al. 117:862 doi:10.1172/JCI31750 [Go to this article.]

Figure 1
HIF activity under hypoxic and normoxic conditions. In normoxia, hydroxylation at 2 proline residues promotes HIF-α association with pVHL and HIF-α destruction via the ubiquitin/proteasome pathway, while hydroxylation of an asparagine residue blocks association with coactivators. In hypoxia, these processes are suppressed, allowing HIF-α subunits (both HIF-1α and HIF-2α) to escape proteolysis, dimerize with HIF-1β, recruit coactivators, and activate transcription via HREs. N, asparagine; P, proline; OH, hydroxyl group; Ub, ubiquitin.