Format

Send to

Choose Destination
Mol Cell. 2007 Apr 13;26(1):63-74.

Regulation of HIF-1alpha stability through S-nitrosylation.

Author information

1
Department of Radiation Oncology, University of Colorado Health Sciences Center, Aurora, CO 80045, USA.

Abstract

Hypoxia-inducible factor 1 (HIF-1) is a master transcriptional factor. Under normal oxygen tension, HIF-1 activity is usually suppressed due to the rapid, oxygen-dependent degradation of one of its two subunits, HIF-1alpha. Here we report that normoxic HIF-1 activity can be upregulated through NO-mediated S-nitrosylation and stabilization of HIF-1alpha. In murine tumors, exposure to ionizing radiation stimulated the generation of NO in tumor-associated macrophages. As a result, the HIF-1alpha protein is S-nitrosylated at Cys533 (through "biotin switch" assay) in the oxygen-dependent degradation domain, which prevents its destruction. Importantly, this mechanism appears to be independent of the prolylhydroxylase-based pathway that is involved in oxygen-dependent regulation of HIF-1alpha. Selective disruption of this S-nitrosylation significantly attenuated both radiation-induced and macrophage-induced activation of HIF-1alpha. This interaction between NO and HIF-1 sheds new light on their involvement in tumor response to treatment as well as mammalian inflammation process in general.

PMID:
17434127
PMCID:
PMC2905600
DOI:
10.1016/j.molcel.2007.02.024
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center