Rhythmic binding of CLOCK-BMAL1 to DNA sites controls daily Dbp gene activity and DNA structure changes

Circadian regulation of the mouse Dbp gene involves rhythmic binding of BMAL1 and CLOCK proteins.

• BMAL1 and CLOCK proteins rhythmically bind to multiple E boxes associated with the Dbp gene.
• Daily changes in chromatin structure are observed, with acetylation of histone H3 at Lys9 and trimethylation at Lys4 during transcription activation.
• A reduction in histone density occurs during the transcription cycle of the Dbp gene.
• Daily repression of Dbp transcription is marked by dimethylation of histone H3 at Lys9 and increased binding of heterochromatin protein 1alpha.
• The conversion of chromatin from a transcriptionally active state to facultative heterochromatin is dependent on functional BMAL1-CLOCK binding sites.

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