Flux Analysis of Hypoxia Response Network.

The availability of cellular oxygen regulates many physiological processes. Oxygen deficiency, i.e., hypoxia, induces expression of a set of genes that are involved in angiogenesis and metabolism. Here we report a detailed flux analysis on a theoretical model on hypoxia response network proposed by Kohn et al. The network is decomposed into smaller underlying pathways which are amenable to direct analytical calculations and capture the essence of the original larger network as observed in numerical simulations. Our analysis elucidates a generic mechanism for the switch-like response of gene up-regulation to hypoxia.