These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Hypoxia-inducible factor-1alpha obstructs a Wnt signaling pathway by inhibiting the hARD1-mediated activation of beta-catenin.
    Author: Lim JH, Chun YS, Park JW.
    Journal: Cancer Res; 2008 Jul 01; 68(13):5177-84. PubMed ID: 18593917.
    Abstract:
    Although a splice variant of mouse mARD1s was found to acetylate and destabilize hypoxia-inducible factor-1alpha (HIF-1alpha), human hARD1 has no such activities. Nonetheless, hARD1 has been reported to bind directly with HIF-1alpha. Here, we addressed the functional significance of the hARD1-HIF-1alpha interaction. Because hARD1 acetylates and activates beta-catenin, we examined whether HIF-1alpha regulates the hARD1-mediated activation of Wnt signaling. It was found that HIF-1alpha binds hARD1 through the oxygen-dependent degradation domain and, in so doing, dissociates hARD1 from beta-catenin, which prevents beta-catenin acetylation. In LiCl-stimulated HEK293 or cancer cell lines with active Wnt signaling, beta-catenin acetylation and activity were suppressed in hypoxia, and these suppressions were mediated by HIF-1alpha. Moreover, HIF-1alpha disruption of hARD1/beta-catenin repressed TCF4 activity, resulting in c-Myc suppression and p21(cip1) induction. In addition, we confirmed that the HIF-1alpha NH(2) terminal inactivates TCF4 by directly binding beta-catenin. In conclusion, HIF-1alpha was found to inactivate the Wnt signaling by binding to hARD1 or beta-catenin, which may contribute to the hypoxia-induced growth arrest of tumor cells.
    [Abstract] [Full Text] [Related] [New Search]