RT Journal Article
SR Electronic
T1 Dissecting a Core Oscillator
JF Science's STKE
JO Sci. STKE
FD American Association for the Advancement of Science
SP tw407
OP tw407
DO 10.1126/stke.4112007tw407
VO 2007
IS 411
A1 Purnell, Beverly A.
YR 2007
UL http://stke.sciencemag.org/content/2007/411/tw407.abstract
AB The core circadian oscillator of the cyanobacterium Synechococcus elongatus can be reconstituted in vitro by mixing the proteins KaiA, KaiB, and KaiC, resulting in oscillations in KaiC phosphorylation. The underlying mechanism of this biochemical oscillator has been elusive. Rust et al. (see the Perspective by Poon and Ferrell) now show that phosphorylation of KaiC at two residues is cyclically ordered and that the abundance of each phosphorylated form determines the phase of the oscillator. This sequential phosphorylation of KaiC, combined with negative feedback caused by one of the phosphorylation states, is sufficient to explain stable oscillation. M. J. Rust, J. S. Markson, W. S. Lane, D. S. Fisher, E. K. O'Shea, Ordered phosphorylation governs oscillation of a three-protein circadian clock. Science 318, 809-812 (2007). [Abstract] [Full Text] A. C. Poon, J. E. Ferrell Jr., A clock with a flip switch. Science 318, 757-758 (2007). [Summary] [Full Text]