HIF3 Alpha (HIF3A) Antibody – Rabbit Polyclonal

The protein encoded by this gene is the alpha-3 subunit of one of several alpha/beta-subunit heterodimeric transcription factors that regulate many adaptive responses to low oxygen tension (hypoxia). The alpha-3 subunit lacks the transactivation domain found in factors containing either the alpha-1 or alpha-2 subunits. It is thought that factors containing the alpha-3 subunit are negative regulators of hypoxia-inducible gene expression. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Mar 2011]

HIF3A: Involved in adaptive response to hypoxia. Suppresses hypoxia-inducible expression of HIF1A and EPAS1. Binds to core DNA sequence 5'-TACGTG-3' within the hypoxia response element (HRE) of target gene promoters. The complex HIF3A-ARNT activates the transcription of reporter genes driven by HRE. Isoform 4 has a dominant-negative function of inactivating HIF1A-mediated transcription. Isoform 4 attenuates the binding of HIF1A to hypoxia-responsive elements (HRE), thus inhibiting HRE-driven transcription. Hypoxia induces down-regulation of isoform 4, leading to activation of HIF1A in hypoxia. Conversely, upon restoring normoxia, the expression of isoform 4 increases and thereby secure an inhibition of HIF1A activity. Isoform 4 may be a negative regulator of hypoxia-inducible gene expression in the kidney and may be involved in renal tumorigenesis. Functions as an inhibitor of angiogenesis in the cornea. 7 isoforms of the human protein are produced by alternative splicing.

Protein type: Tumor suppressor; Transcription factor

Chromosomal Location of Human Ortholog: 19q13.32

Cellular Component: nucleoplasm; cytosol

Molecular Function: protein dimerization activity; signal transducer activity; DNA binding; transcription coactivator activity; transcription corepressor activity; transcription factor activity

Biological Process: regulation of transcription from RNA polymerase II promoter; transcription from RNA polymerase II promoter; signal transduction