Synchronization of oscillators and its molecular mechanism(s) in cyanobacteria

Abstract

Prokaryotic cyanobacteria have been studied as the simplest organisms that exhibit circadian rhythms. The central S.elongatus clock is comprised of at least three components, the proteins KaiA, KaiB and KaiC. The phosphorylation status of KaiC can sustain a ca. 24-hour period in vitro with the presence of the two other Kai proteins and ATP. Synchronization of different oscillators can be achieved by mixing two KaiABC in vitro samples that are in different phosphorylation phases, with prior results indicating that their rhythms continue, yet with a synchronized shared phase. I have focused on investigating the synchronization of oscillators with different periods in vivo and in vitro with the goal of elucidating the underlying mechanisms. Interdisciplinary approaches including molecular biology, biochemistry and computational simulation are combined to demonstrate that co-existence of two oscillators with different periods displays a robustly synchronized rhythm with an intermediate period both in vivo and in vitro. Moreover, the computationally simulated results agree with the in vitro experiment, and imply that monomer exchange may work together with KaiA sequestration to secure the molecular synchronization of KaiC population in the in vitro reaction.