Function
Hypoxia-Inducible factor 1 alpha inhibitor (FIH-1) is an inhibitor of Hypoxia-Inducible Factors 1 alpha (HIF-1). HIF-1 is a master regulator of oxygen homeostasis via transcription activation. Thus, FIH-1 is an inhibitor of transcriptional activation [1].
Relevance
The interaction of FIH-1 with notch 1 suggests that it may play a critical role in controlling the survival of vascular endothelial cells and thus may be used in antiangiogenic strategies in controlling cancer and rheumatoid arthritis[2]. FIH-1 acts as a tumor suppressor in human colorectal cancer[3].
Structural highlights
The 3D structure of the complex between FIH-1 and the C-terminal transactivation domain of HIF-1 shows 2 interaction sites between the two proteins. The buried hydroxylation site which includes the Asn which undergoes hydroxylation and a surface interaction site [4].