The Effects of Hypoxia on the Immune-Modulatory Properties of Bone Marrow-Derived Mesenchymal Stromal Cells

Figure 1

Hydroxylation-mediated regulation of the HIF-α subunits. The primary posttranslational regulation of the HIF-α polypeptides is mediated by the prolyl-4-hydroxlase-1, prolyl-4-hydroxlase-2, and prolyl-4-hydroxlase-3 (PHDs) that catalyze the hydroxylation of conserved proline residues. This leads to the ubiquitylation and subsequent proteasomal degradation of the HIF-α subunits in the presence of oxygen. A complimentary hydroxylation catalyzed by the asparagine hydroxylase termed factor inhibiting HIF (FIH) that prevents the association of HIFs with their transcriptional coactivator p300.