Figure 2. REV-ERBα is required for normal expression of CLOCK.

HepG2 cells were transfected with siRNAs targeting RORα (78% reduction), RORγ (50% reduction) and REV-ERBα (57% reduction) to reduce their expression. CLOCK expression was then examined by RT-PCR. CLOCK expression was elevated when REV-ERBα expression was reduced (c), but unaffected by alteration of RORα (a) expression or RORγ (b). Data shown is mean ± SEM where n = 4. (d) ChIP assay illustrating REV-ERBα and NCoR occupancy of the 1^st intron of the CLOCK gene. (e) The synthetic REV-ERBα agonist GSK4112 suppresses CLOCK gene expression in HepG2 cells. *, p<0.05.