CLOCK: Proteins and Enzymes

Clock is an essential regulator of circadian rhythms. Clock is a basic helix-loop-helix-PAS transcription factor that heterodimerizes with BMAL1. Together these transcription factors bind to E box elements (CACGTG) within the promoter of circadian genes (period1 and 2) stimulating their transcription. BMAL dimerization is necessary for Clock's nuclear translocation, E box dependent transcription, phosphorylation, and degradation.