Molecular regulation of the Fabp7 promoter.

(A) The top panel depicts the murine Fabp7 (mFabp7) promoter with its two REV-ERBα response elements (ROREs). Transactivation experiments in NG108-15 neurobalstoma cells show a repression potential of REV-ERBα that is similar for both the Bmal1::luc and Fabp7::luc reporter constructs (n = 3, *p<0.05, mean ± SD). (B) Deletion of the RORE element 257 nucleotides upstream of the transcription start site of Fabp7 (Fabp7ΔRORE) abolishes the repression by REV-ERBα (n = 3, *p<0.05, mean ± SD). (C) RORα activates the Fabp7::luc reporter in a similar fashion as the Bmal1::luc reporter (n = 3, *p<0.05, mean ± SD). (D) Real-time monitoring of NIH 3T3 cells transfected with the Bmal1::luc and Fabp7::luc reporters, respectively. (E) Chromatin immunoprecipitation (ChIP) reveals time of day dependent binding of REV-ERBα on the Fabp7 promoter in hippocampal tissue (n = 4, ***p<0.001, mean ± SEM, one-way ANOVA). ∅ denotes background binding of REV-ERBα at the unrelated Fgf21 promoter.