Epigenetic control, which includes DNA methylation and histone modifications, 
leads to chromatin remodeling and regulated gene expression. Remodeling of 
chromatin constitutes a critical interface of transducing signals, such as light 
or nutrient availability, and how these are interpreted by the cell to generate 
permissive or silenced states for transcription. CLOCK-BMAL1-mediated activation 
of clock-controlled genes (CCGs) is coupled to circadian changes in histone 
modification at their promoters. Several chromatin modifiers, such as the 
deacetylases SIRT1 and HDAC3 or methyltransferase MLL1, have been shown to be 
recruited to the promoters of the CCGs in a circadian manner. Interestingly, the 
central element of the core clock machinery, the transcription factor CLOCK, 
also possesses histone acetyltransferase activity. Rhythmic expression of the 
CCGs is abolished in the absence of these chromatin modifiers. Here we will 
discuss the evidence demonstrating that chromatin remodeling is at the 
crossroads of circadian rhythms and regulation of metabolism and cellular 
proliferation.