Coactivators necessary for transcriptional output of the hypoxia inducible factor, HIF, are directly recruited by ARNT PAS-B

Carrie L. Partch, Kevin H. Gardner

Research output: Contribution to journalArticle

42 Scopus citations


Hypoxia-inducible factor (HIF) is the key transcriptional effector of the hypoxia response in eukaryotes, coordinating the expression of genes involved in oxygen transport, glycolysis, and angiogenesis to promote adaptation to low oxygen levels. HIF is a basic helix-loop-helix (bHLH)-PAS (PER-ARNT-SIM) heterodimer composed of an oxygen-labile HIF-α subunit and a constitutively expressed aryl hydrocarbon receptor nuclear translocator (ARNT) subunit, which dimerize via basic helix-loop-helix and PAS domains, and recruit coactivators via HIF-α C-terminal transactivation domains. Here we demonstrate that the ARNT PAS-B domain provides an additional recruitment site by binding the coactivator transforming acidic coiled-coil 3 (TACC3) in a step necessary for transcriptional responses to hypoxia. Structural insights from NMR spectroscopy illustrate how this PAS domain simultaneously mediates interactions with HIF-α and TACC3. Finally, mutations on ARNT PAS-B modulate coactivator selectivity and target gene induction by HIF in vivo, demonstrating a bifunctional role for transcriptional regulation by PAS domains within bHLH-PAS transcription factors.

Original languageEnglish (US)
Pages (from-to)7739-7744
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number19
Publication statusPublished - May 10 2011



  • Bifunctional interactions
  • Protein/protein interactions
  • Transcriptional coactivators

ASJC Scopus subject areas

  • General

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