Open AccessFunctioning and robustness of a bacterial circadian clock
Author(s) -
Clodong Sébastien,
Dühring Ulf,
Kronk Luiza,
Wilde Annegret,
Axmann Ilka,
Herzel Hanspeter,
Kollmann Markus
Publication year - 2007
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb4100128
Subject(s) - robustness (evolution) , biology , circadian clock , circadian rhythm , in silico , systems biology , computational biology , biological clock , microbiology and biotechnology , synthetic biology , biological system , neuroscience , biochemistry , gene
Cyanobacteria are the simplest known cellular systems that regulate their biological activities in daily cycles. For the cyanobacterium Synechococcus elongatus , it has been shown by in vitro and in vivo experiments that the basic circadian timing process is based on rhythmic phosphorylation of KaiC hexamers. Despite the excellent experimental work, a full systems level understanding of the in vitro clock is still lacking. In this work, we provide a mathematical approach to scan different hypothetical mechanisms for the primary circadian oscillator, starting from experimentally established molecular properties of the clock proteins. Although optimised for highest performance, only one of the in silico ‐generated reaction networks was able to reproduce the experimentally found high amplitude and robustness against perturbations. In this reaction network, a negative feedback synchronises the phosphorylation level of the individual hexamers and has indeed been realised in S. elongatus by KaiA sequestration as confirmed by experiments.