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Updated: Aug 11, 2026
10:38
Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters
Published on: September 27, 2012
Direct association between mouse PERIOD and CKIepsilon is critical for a functioning circadian clock
Choogon Lee1, David R Weaver, Steven M Reppert
1Department of Neurobiology, LRB-728, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
Molecular and Cellular Biology
|January 1, 2004
Summary
Mouse PER3 protein is regulated by mPER1 at a posttranslational level, impacting circadian clock function. This regulation is crucial for maintaining molecular rhythmicity and proper clock function.
Area of Science:
- Chronobiology
- Molecular Biology
- Biochemistry
Background:
- The circadian clock mechanism relies on core clock proteins like mPER1, mPER2, and mPER3.
- While mPER1 and mPER2 are essential, mPER3 has been considered expendable in circadian rhythms.
Purpose of the Study:
- To investigate the posttranslational regulation of mPER3 in mouse liver.
- To compare mPER3 regulation with mPER1 and mPER2 to identify key features for circadian clock function.
Main Methods:
- In vivo studies in mouse liver.
- Analysis of protein phosphorylation and cellular localization.
- Interaction studies with other clock proteins.
- In vitro studies using chimeric proteins.
Main Results:
- mPER3 exhibits time-dependent phosphorylation, cellular translocation, and interactions, similar to mPER1 and mPER2.
- mPER1 or mPER2 alone can maintain rhythmic posttranslational events.
- mPER3 cannot sustain molecular rhythmicity in mPer1/2 double-mutant mice.
- mPER3 is constitutively cytoplasmic and unphosphorylated in mPer1-deficient mice.
- mPER3's inability to support clock function is partly due to a lack of direct interaction with casein kinase Iepsilon (CKIepsilon).
Conclusions:
- mPER3 is regulated by mPER1 at a posttranslational level.
- The casein kinase Iepsilon (CKIepsilon)-binding domain is critical for mPER phosphorylation and circadian clock function.
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