- Authors: Kenneth, N. S., Mudie, S., van Uden, P., Rocha, S.
- Year: 2009
- Journal: J Biol Chem 284 4123-31
- Applications: in vitro / siRNA / INTERFERin
- Cell type: U-2 OS
Description: Human bone osteosarcoma
Known as: U2OS
Hypoxia induces a variety of cellular responses such as cell cycle arrest, apoptosis, and autophagy. Most of these responses are mediated by the hypoxia-inducible factor-1alpha. To induce target genes, hypoxia-inducible factor-1alpha requires a chromatin environment conducive to allow binding to specific sequences. Here, we have studied the role of the chromatin-remodeling complex SWI/SNF in the cellular response to hypoxia. We find that SWI/SNF is required for several of the cellular responses induced by hypoxia. Surprisingly, hypoxia-inducible factor-1alpha is a direct target of the SWI/SNF chromatin-remodeling complex. SWI/SNF components are found associated with the hypoxia-inducible factor-1alpha promoter and modulation of SWI/SNF levels results in pronounced changes in hypoxia-inducible factor-1alpha expression and its ability to transactivate target genes. Furthermore, impairment of SWI/SNF function renders cells resistant to hypoxia-induced cell cycle arrest. These results reveal a previously uncharacterized dependence of hypoxia signaling on the SWI/SNF complex and demonstrate a new level of control over the hypoxia-inducible factor-1alpha system.