Cryptochrome and Period Proteins Are Regulated by the CLOCK/BMAL1 Gene: Crosstalk between the PPARs/RXR𝛼-Regulated and CLOCK/BMAL1-Regulated Systems

Figure 5

Dose-dependent changes in activity of the cellular retinol binding protein II (CRBPII) promoter in human kidney 293T cells induced by the CLOCK/BMAL1 gene (0–140 ng) plus the PPAR𝛼/RXR𝛼 gene (50 ng). The del-0-CRBPII-Luc plasmid contained no repeat sequences (5^′-AG(G/T)TCA-3^′); the del-1-CRBPII-Luc plasmid contained one repeat sequence (5^′-AG(G/T)TCA-3^′); the del-2-CRBPII-Luc plasmid contained two repeat sequences (5^′-AG(G/T)TCA-3^′); the del-3-CRBPII-Luc plasmid contained three repeat sequences (5^′-AG(G/T)TCA-3^′), and the del-4-CRBPII-Luc plasmid contained four repeat sequences (5^′-AG(G/T)TCA-3^′). The luciferase activity of all pCRBPII-Luc plasmids was normalized to the luciferase activity of pRL-TK. Experiments were performed in triplicate, and four independent experiments were performed. All data are means ± SD.