High resolution

Module 6: Figure circadian clock molecular mechanism

Molecular mechanisms responsible for the driving the circadian clock.

The circadian clock depends upon a series of feedback loops that couple together the transcription and expression of the different clock genes. On the right is the regulatory feedback system that controls the expression and function of the Per and Cry genes (Steps 1–5). On the left are the regulatory loops that control the action of the BMAL1 gene (Steps 5–10). The BMAL1/CLOCK heterodimer binds to the E-box enhancer sequence CACGTG. See the text for details of these two regulatory loops.