Regulation of Transcriptional Activity of Hypoxia-Inducible Factor 1

Hypoxia-inducible factor 1 (HIF-1) is a master regulator of oxygen homeostasis induced by hypoxia, and it plays a critical role in controlling oxygen delivery and metabolic adaptation of tumor cells to hypoxic conditions.Although HIF-1 is a heterodimer composed of a and β subunits, only HIF-1 a is regulated by oxygen tension and the regulation of HIF-1α occurs at post-trans-lational level, involving modifications of hydroxylation, acetylation and phosphorylation.In addition, it was discovered that phosphatidylinositol 3-kinase/Akt pathway is involved in the HIF-1 trans-activation.The study of HIF-1 regulation will help us to get an insight into the molecular mechanisms responsible for the adaptation of tumor cells to hypoxia.