The intricate dance of post-translational modifications in the rhythm of life.

Endogenous biological rhythms with approximately 24-h periodicity are generated by the circadian clock, in which clock genes coordinate with one another and form a transcriptional-translational negative feedback loop. The precision of the circadian clock is further regulated by multiple post-translational modifications (PTMs), including phosphorylation, ubiquitination, acetylation and SUMOylation. Here, we review current understanding of the regulatory mechanisms of the core clock proteins by PTMs in the mammalian circadian clock.