Figure 10.

Circadian clock feedback involves targeted reconstitution of NuRD by the PER complex. (A) During the circadian transcriptional activation phase, the transcription factors Clock-Bmal1 assemble with the NuRD subunits Chd4 and Mta2 at the E-box of the circadian target genes Per1/Per2. Under this condition, Chd4 promotes Clock-Bmal1 transcriptional activity. Mta2 is necessary for the subsequent assembly of NuRD repressor. (B) During the circadian negative feedback phase, newly formed PER complex brings the remaining NuRD components to Clock-Bmal1 at the E-box and reconstitutes functional NuRD repressor. Repressor activity of the PER complex thus depends on correct targeting of Clock-Bmal1. Model adapted from Kim et al. (2014), license number 4578121170114.