HIF-1, O(2), and the 3 PHDs: how animal cells signal hypoxia to the nucleus

Hypoxia-inducible factor 1 (HIF-1) is a global regulator of cellular and systemic O(2) homeostasis in animals. A molecular basis for O(2)-regulated expression of the HIF-1 alpha subunit has now been determined, providing a mechanism for changes in gene expression in response to changes in cellular oxygenation.