6e3t
From Proteopedia
Crystal Structure of the Heterodimeric HIF-2 Complex with Antagonist T1001
Structural highlights
Function[ARNT_MOUSE] Required for activity of the Ah (dioxin) receptor. This protein is 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. The heterodimer with HIF1A or EPAS1/HIF2A functions as a transcriptional regulator of the adaptive response to hypoxia (By similarity). [EPAS1_MOUSE] Transcription factor involved in the induction of oxygen regulated genes. Binds to core DNA sequence 5'-[AG]CGTG-3' within the hypoxia response element (HRE) of target gene promoters. Regulates the vascular endothelial growth factor (VEGF) expression and seems to be implicated in the development of blood vessels and the tubular system of lung. May also play a role in the formation of the endothelium that gives rise to the blood brain barrier. Potent activator of the Tie-2 tyrosine kinase expression. Activation requires recruitment of transcriptional coactivators such as CREBPB and probably EP300. Interaction with redox regulatory protein APEX seems to activate CTAD (By similarity). Publication Abstract from PubMedHypoxia-inducible factor-2 (HIF-2) is a heterodimeric transcription factor formed through dimerization between an oxygen-sensitive HIF-2alpha subunit and its obligate partner subunit ARNT. Enhanced HIF-2 activity drives some cancers, whereas reduced activity causes anemia in chronic kidney disease. Therefore, modulation of HIF-2 activity via direct-binding ligands could provide many new therapeutic benefits. Here, we explored HIF-2alpha chemical ligands using combined crystallographic, biophysical, and cell-based functional studies. We found chemically unrelated antagonists to employ the same mechanism of action. Their binding displaced residue M252 from inside the HIF-2alpha PAS-B pocket toward the ARNT subunit to weaken heterodimerization. We also identified first-in-class HIF-2alpha agonists and found that they significantly displaced pocket residue Y281. Its dramatic side chain movement increases heterodimerization stability and transcriptional activity. Our findings show that despite binding to the same HIF-2alpha PAS-B pocket, ligands can manifest as inhibitors versus activators by mobilizing different pocket residues to allosterically alter HIF-2alpha-ARNT heterodimerization. Bidirectional modulation of HIF-2 activity through chemical ligands.,Wu D, Su X, Lu J, Li S, Hood BL, Vasile S, Potluri N, Diao X, Kim Y, Khorasanizadeh S, Rastinejad F Nat Chem Biol. 2019 Feb 25. pii: 10.1038/s41589-019-0234-5. doi:, 10.1038/s41589-019-0234-5. PMID:30804532[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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