University of California, Irvine (UCI) researchers identified the chemical switch that triggers the genetic mechanism regulating our internal body clock.
About 10–15% of all human genes are regulated by circadian rhythms, according to the researchers. Disruption of these rhythms can influence human health and has been linked to insomnia, depression, heart disease, cancer, and neurodegenerative disorders.
The gene CLOCK and its partner BMAL1 trigger circadian rhythms. The UCI team discovered last year that CLOCK functions as an enzyme that modifies chromatin.
In the current study, the investigators learned that a single amino acid in the BMAL1 protein undergoes a modification that triggers the genetic chain of events involved with circadian rhythms. The researchers note that if this amino-acid modification is impaired in any way, the switching mechanism can be thrown off, which can be the genetic underpinning of circadian-rhythm-related ailments.
The study will appear in the December 13 issue of Nature.