A pacemaker regulates the circadian rhythms in mammals and so far four clock-gene families have been identified. Now, in October 24
Honma et al. examined the effects of Dec1 and Dec2 and observed that these transcription factors repressed Clock/Bmal1-induced transactivation of the mouse Per1 promoter through direct protein–protein interactions with Bmal1 and/or competition for E-box elements. In addition, they showed that Dec1 and Dec2 are expressed in the suprachiasmic nucleus in a circadian fashion.
"The repressive effect of the Decs on circadian transcription suggests that they are negative clock components," writes J.D. Alvarez at the Hospital...