Anti-HAF/SART1 Antibody, clone 1-2 clone 1-2, from mouse

U4/U6.U5 tri-snRNP-associated protein 1 (UniProt O43290; also known as Allergen Hom s 1, HAF, hSART-1, hSnu66, Hypoxia-associated factor, SART-1, SNU66 homolog, Squamous cell carcinoma antigen recognized by T-cells 1, U4/U6.U5 tri-snRNP-associated 110 kDa protein) is encoded by the SART1 (also known as HAF) gene (Gene ID 9092) in human. The hypoxia-associated factor (HAF) is an E3 ubiquitin ligase that mediates the ubiquitination and degradation of hypoxia-inducible factor 1alpha (HIF-1alpha). HAF also binds to HIF-2alpha and promotes HIF-2 transactivation instead of promoting HIF-2alpha degradation. In addition, hypoxia-dependent HAF SUMOylation enhances HAF interaction with HIF-2alpha and induction of HIF-2 target genes transcription, such as OCT-3/4, SOX2 and NANOG. HAF therefore promotes stem cell characteristics, aggressive tumor growth and invasion by switching cells from HIF-1alpha- to HIF-2alpha-dependent signaling. HAF overexpression enhances glioblastoma cells that express both HIF-1alpha and HIF-2alpha to initiate tumors as intracranial xenografts in mice. On the other hand, HAF overexpression results in decreased xenograft tumor growth of HT29 colon carcinoma cells that only express HIF-1alpha.