a bHLH transcription factor that requires dimerization with another bHLH protein for efficient DNA binding. A binding partner for the Ah (dioxin) nuclear receptor. Required for the ligand-binding subunit to translocate from the cytosol to the nucleus after ligand binding. The complex then initiates transcription of genes involved in the activation of PAH procarcinogens. A binding partner for HIF1A or HIF2A, transcription factors that regulates transcription from RNA polymerase II promoter in the adaptive response to hypoxia and oxidative stress. This complex activates target genes that limit oxygen consumption. HIF-1alpha may have nontranscriptional activities that inhibit DNA replication and cell proliferation when oxygen becomes scarce. Forms heterodimers with other bHLH proteins. Interacts with TACC3. Three isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: DNA binding protein; Transcription factor; Motility/polarity/chemotaxis; Nuclear receptor
Molecular Function: RNA polymerase II transcription factor activity, enhancer binding; protein binding; aryl hydrocarbon receptor binding; sequence-specific DNA binding; protein heterodimerization activity; transcription coactivator activity; aryl hydrocarbon receptor activity; transcription factor activity; transcription factor binding
Biological Process: embryonic placenta development; transcription, DNA-dependent; positive regulation of erythrocyte differentiation; positive regulation of transcription, DNA-dependent; mRNA transcription from RNA polymerase II promoter; positive regulation of vascular endothelial growth factor receptor signaling pathway; positive regulation of protein sumoylation; positive regulation of hormone biosynthetic process; positive regulation of glycolysis; response to hypoxia; positive regulation of endothelial cell proliferation; positive regulation of transcription from RNA polymerase II promoter; regulation of transcription from RNA polymerase II promoter in response to oxidative stress; cell differentiation
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.