PLoS Computational Biology
The temperature compensated in vitro oscillation of cyanobacterial KaiC phosphorylation, the first example of a thermodynamically closed system showing circadian rhythmicity, only involves the three Kai proteins (KaiA, KaiB, and KaiC) and ATP. In this paper, we describe a model in which the KaiA- and KaiB-assisted autocatalytic phosphorylation and dephosphorylation of KaiC are the source for circadian rhythmicity. This model, based upon autocatalysis instead of transcription-translation negative feedback, shows temperature-compensated circadian limit-cycle oscillations with KaiC phosphorylation profiles and has period lengths and rate constant values that are consistent with experimental observations.
Mehra, Arun; Hong, Christian I.; Shi, Mi; Loros, Jennifer J.; Dunlap, Jay C.; and Ruoff, Peter, "Circadian Rhythmicity by Autocatalysis" (2006). Open Dartmouth: Faculty Open Access Articles. 1400.