Figure 5.
Identification of HRE sites in the Smox promoter. (A) Six potential HRE sites located in the rat Smox promoter in the sequence analysis. (B) Luciferase assay for the transcriptional activity of the Smox promoter in TR-MUL5 cells under either normoxic or hypoxic conditions for 24 hours (20% O2 or 1% O2). (C) Effects of Hif1a silencing on Smox expression in TR-MUL5 cells under hypoxic condition (1% O2) for 24 hours. (D) Mutant luciferase constructs designed for each of the six HRE sites via site-direct mutagenesis using the –1067 Luc reporter plasmid as a backbone. (E) Effects of Smox promoter mutations on the Smox transcriptional activity in TR-MUL5 cells stimulated with hypoxia for 24 hours. n = 6 in each group. **P < 0.01.