The interplay between diet, epigenetics and the circadian clock

Abstract The circadian clock is an internal timing mechanism that generates ∼24-h oscillations in behavior and physiology to coordinate with the day-night cycle. Importantly, the circadian clock is a key regulator of energy metabolism whose dysfunction due to environmental and genetic factors results in metabolic disease. Mechanistically, the circadian clock is a cell-autonomous transcription-translation oscillatory circuit that impinges on energy metabolism in large part through control of gene expression. As with other transcriptional mechanisms, circadian control of transcription - both in terms of the circadian clock itself as well as off-clock target genes - involves dynamic regulation of chromatin structure. As various histone modifying enzymes use intermediate energy metabolites as co-factors, epigenetic regulation thus constitutes a mechanism through which the circadian clock and energy metabolism are integrated.