Circadian Rhythmicity by Autocatalysis
Author Information
Author(s): Mehra Arun, Hong Christian I, Shi Mi, Loros Jennifer J, Dunlap Jay C, Ruoff Peter
Primary Institution: Dartmouth Medical School
Hypothesis
The study proposes a model where the autocatalytic phosphorylation and dephosphorylation of KaiC proteins are the source of circadian rhythmicity.
Conclusion
The model successfully explains temperature-compensated circadian oscillations in KaiC phosphorylation based on autocatalysis.
Supporting Evidence
- The model predicts that the period length and the ratio of phosphorylated to unphosphorylated KaiC are linked to the stability of the ternary complex formed by the Kai proteins.
- The study demonstrates that the KaiC oscillator can be reconstituted in vitro, showing temperature compensation.
- The model suggests that autocatalysis is essential for sustained oscillations in the KaiC phosphorylation rhythm.
Takeaway
This study shows how a simple system of proteins can create a biological clock that keeps time, even when the temperature changes.
Methodology
The study developed a deterministic model based on known interactions and phosphorylation events among Kai proteins.
Limitations
The model's complexity may not capture all biological nuances, and some rate constants are not well-defined.
Digital Object Identifier (DOI)
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