1, 9 PA enhances HIF-1α ubiquitination.

(A). A431 cells were treated with 10 µM 1, 9 PA for indicated time period. Cell lysates were prepared for HIF-1α immunoprecipitation, followed by Western blotting of the immunoprecipitates with antibodies directed against ubiquitin (top), HIF-1α, and β-actin. (B) A431 cells were untreated or treated with 10 µM 1, 9 PA in the presence of 10 µM MG132 for 1 h in 0.5% FBS medium. HIF-1α was immunoprecipitated followed by Western blot analysis with an anti-HIF-1α antibody.