Hypoxia Inducible Factor-1: The guardian working in hypoxia

Hypoxiainducible factor 1 (HIF-1) is an important transcription factor that is expressed upon hypoxia. HIF-1 is a heterodimer of HIF-1α subunit and HIF-1β subunit. HIF-1α is unique to HIF-1 whereas HIF-1β is also known as aryl hydrocarbon receptor (AhR) nuclear translocator (ARNT) gene product. HIF-1β can dimerize with AhR to form AhR complex and can also dimerize with HIF-1α to form HIF-1. HIF-1α subunit and HIF-1β subunit both have basic helixloop-helix (bHLH) and PAS (Per-Arnt-Sim) domain, which are important for DNA binding and dimerization. These two domains are located at the amino-terminal half of each protein. The carboxyl-terminal half of HIF-1α as well as of HIF-1β is important for transactivation and regulation. This paper is focusing on the biochemical and structural properties of HIF-1.