Related Experiment Video
Updated: Aug 10, 2026

Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
Light and circadian rhythmicity regulate MAP kinase activation in the suprachiasmatic nuclei
K Obrietan1, S Impey, D R Storm
1Department of Pharmacology, University of Washington, Seattle 98195-7280, USA.
Abstract:
Although the circadian time-keeping properties of the suprachiasmatic nuclei (SCN) require gene expression, little is known about the signal transduction pathways that initiate transcription. Here we report that a brief exposure to light during the subjective night, but not during the subjective day, activates the p44/42 mitogen-activated protein kinase (MAPK) signaling cascade in the SCN. In addition, MAPK stimulation activates CREB (cAMP response element binding protein), indicating that potential downstream transcription factors are stimulated by the MAPK pathway in the SCN. We also observed striking circadian variations in MAPK activity within the SCN, suggesting that the MAPK cascade is involved in clock rhythmicity.
Related Concept Videos
Biological Clocks and Seasonal Responses
Circadian Rhythms and Gene Regulation
M-Cdk Drives Transition Into Mitosis
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
MAPK Signaling Cascades
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...

