Circadian clock genes (CCGs)

Circadian clock genes comprise a network of genes and proteins that orchestrate 24-hour biological rhythms in nearly all cells of the body (NIH, 2023). The core molecular machinery is driven by a transcription-translation feedback loop (TTFL) where the CLOCK and BMAL1 proteins activate the transcription of Period (PER) and Cryptochrome (CRY) genes, which then feedback to inhibit their own expression (Takahashi, 2017). This system regulates critical physiological processes including metabolism, immune response, and the sleep-wake cycle. Dysregulation of these genes is associated with a wide range of conditions, including metabolic syndrome, cardiovascular disease, and various cancers (Nature Reviews Drug Discovery, 2019). Therapeutic strategies involve small molecules that target specific clock components, such as REV-ERB and ROR nuclear receptors or Casein Kinase 1, to reset or stabilize the clock. While promising, targeting the circadian system requires careful consideration of timing (chronotherapy) to avoid systemic misalignment and potential side effects on sleep and mood.

Other names

Clock genesCircadian rhythm genesCore clock componentsMolecular clock genes

Modulation of the core transcription-translation feedback loop (TTFL) through agonism or antagonism of nuclear receptors (REV-ERB, ROR), inhibition of regulatory kinases (CK1 delta/epsilon), or activation of melatonin receptors to phase-shift the central clock.