title: Circadian rhythmicity by autocatalysis.
abstract: 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.
authors.affiliation: Department of Genetics, Dartmouth Medical School, Hanover, New Hampshire, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Mehra
authors.forename: Christian I
authors.initials: CI
authors.lastname: Hong
authors.forename: Mi
authors.initials: M
authors.lastname: Shi
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Loros
authors.forename: Jay C
authors.initials: JC
authors.lastname: Dunlap
authors.forename: Peter
authors.initials: P
authors.lastname: Ruoff
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001683:Biological Clocks / Q000502:physiology*; D002384:Catalysis; D002940:Circadian Rhythm / Q000502:physiology*; D056925:Circadian Rhythm Signaling Peptides and Proteins; D003198:Computer Simulation; D000458:Cyanobacteria / Q000502:physiology*; D005246:Feedback / Q000502:physiology; D007700:Kinetics; D008954:Models, Biological; D010507:Periodicity; D010766:Phosphorylation; D015398:Signal Transduction; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D056925:Circadian Rhythm Signaling Peptides and Proteins; C114269:KaiA protein, cyanobacteria; C114270:KaiB protein, cyanobacteria; C114271:KaiC protein, cyanobacteria