Elevated ATPase activity of KaiC applies a circadian checkpoint on cell division in Synechococcus elongatus.
A circadian clock coordinates physiology and behavior in diverse groups of living organisms. Another major cyclic cellular event, the cell cycle, is regulated by the circadian clock in the few cases where linkage of these cycles has been studied. In the cyanobacterium Synechococcus elongatus, the circadian clock gates cell division by an unknown mechanism. Using timelapse microscopy, we confirm the gating of cell division in the wild-type and demonstrate the regulation of cytokinesis by key clock components. Specifically, a state of the oscillator protein KaiC that is associated with elevated ATPase activity closes the gate by acting through a known clock output pathway to inhibit FtsZ ring formation at the division site. An activity that stimulates KaiC phosphorylation independently of the KaiA protein was also uncovered. We propose a model that separates the functions of KaiC ATPase and phosphorylation in cell division gating and other circadian behaviors.
Dong
Guogang
G
Center for Biological Clocks Research, Department of Biology, Texas A&M University, College Station, 77843-3258, USA.
Yang
Qiong
Q
Wang
Qiang
Q
Kim
Yong-Ick
YI
Wood
Thammajun L
TL
Osteryoung
Katherine W
KW
van Oudenaarden
Alexander
A
Golden
Susan S
SS
D001426:Bacterial Proteins / Q000378:metabolism*; D001683:Biological Clocks; D002455:Cell Division; D002940:Circadian Rhythm; D056925:Circadian Rhythm Signaling Peptides and Proteins / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism; D046940:Synechococcus / Q000166:cytology* / Q000502:physiology*
D001426:Bacterial Proteins; D056925:Circadian Rhythm Signaling Peptides and Proteins; D003598:Cytoskeletal Proteins; C071525:FtsZ protein, Bacteria; C114271:KaiC protein, cyanobacteria; D011494:Protein Kinases; C411989:CikA protein, bacteria