Circadian rhythms in many organisms, from mushrooms to mammals, are scanned in part on the spending hours of light with those of darkness and the so-called “internal clock” on a 24 hour cycle.
A new study, a collaboration between researchers in Japan Riken Institute, University of Hiroshima and the University of Michigan, led to the discovery of a gene, called Chrono, which plays a crucial role in the regulation of the internal clock at the cellular level. The work was published in “PLoS Biology”.
Inside the cells, in fact, the internal clock is regulated by a complex network of genes and proteins that turn on and off with each other in response to environmental stimulus.
In this new study, the researchers analysed all the genes that represent a target for the action of BMAL1, a molecule that in some previous studies has been shown to participate in the regulation of transcription of many genes to other genes of the internal clock.
So the authors have identified a new gene circadian, Chrono, which set in particular in the mechanisms of negative regulation, namely that inhibit the transcription of genes of the circadian clock in mammals: the protein encoded by the gene Chrono binds to the region of regulation of clock genes and its function of repression varies according to a circadian rhythm.
When the adjustment mechanism is altered, the physiological effects are obvious.
The researchers have found that mice in which the expression of Chrono is in deficit have circadian cycles longer than normal.
In addition, the activity of the gene is affected by some cellular receptors sensitive to glucocorticoids, hormones that are produced by the body under stress, consistent with the fact that circadian rhythms are strongly influenced by environmental stimuli.