Fig. 1.

Deacetylation of HIF-1α by HDAC6 regulates its degradation and transcriptional activity under hypoxia. MEFs were incubated for 24 h in 21% O₂ (a), in 1% O₂ (b), or for 6 h with 500 μM CoCl₂ to mimic hypoxia (c). Whole cell lysates were immunoprecipitated with an anti-HIF-1α antibody. Immunocomplexes were either probed for anti-HIF-1α or anti-acetylated lysine antibody. Whole cell lysates of 10% were used as input control. d MEFs were incubated for 6, 12, or 24 h with 500 μM CoCl₂ to mimic hypoxia or in 21% O₂. Immunoblotting analysis was performed with indicated antibodies. α-Tubulin is used as a loading control. e MEFs were co-transfected with an HRE-firefly luciferase vector and a Renilla vector as a control. Transfected cells were incubated for 24 h in 21% O₂ then incubated for an additional 6 h with 500 μM CoCl₂. Dual luciferase activity was measured, and the ratio of firefly to Renilla was used as the relative luciferase activity. f MEFs were incubated for 6 h with 500 μM CoCl₂ to mimic hypoxia. mRNA expression of HIF-1α target genes was analyzed by qRT-PCR. mRNA values were normalized to that of actin. *P < 0.05 based on two-tailed unpaired Student’s t test