Circadian inhibition of rapid cell cycles due to coupling through Wee1.

<p>The curves show the time course of cyclin B/Cdk1 (red), CLOCK-BMAL1 (green), and the LD cycle (dashed line) when the autonomous period of the cell cycle prior to coupling is equal to 4 h, as in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002516#pcbi-1002516-g006" target="_blank">Fig. 6A</a>, the coupling strength, <i>v</i>_sw, is equal to 0.025 µM h⁻¹ (A) or 0.005 µM h⁻¹ (B). Panels (A) and (B) correspond, respectively, to points H and I in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002516#pcbi-1002516-g004" target="_blank">Fig. 4A</a>. Whereas two peaks in cyclin B/Cdk1 occur in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002516#pcbi-1002516-g006" target="_blank">Fig. 6A</a> at a higher coupling strength for the same autonomous period corresponding to point D in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002516#pcbi-1002516-g004" target="_blank">Fig. 4A</a>, three or four peaks of cyclin B/Cdk1 occur during the L phase of the LD cycle when the coupling strength is progressively decreased. This is due to the accompanying decrease in the peak of the Cdk inhibitor Wee1 associated with the circadian peak in CLOCK-BMAL1 during the L phase. Other parameters values are the same as in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002516#pcbi-1002516-g004" target="_blank">Fig. 4A</a>.