Modeling a Minimal CDK Network

This paper reports a computational analysis of the minimal CDK network engineered in fission yeast (doi:10.1038/nature09543). It had been observed that a Cdk-inhibitory mechanism working through tyrosine phosphorylation of the kinase subunit, which is essential for modern fission yeast, is dispensable in the minimal Cdk network. Developing both deterministic and stochastic models of the minimal Cdk network shows that a different inhibitory mechanism based on a stoichiometric Cdk inhibitor (called Rum1) can compensate for the lack of inhibitory Cdk phosphorylation in the MCN. It also demonstrate that this compensation mechanism is suppressed in wild-type fission yeast cells by the other Cdk-cyclin complexes, which down-regulate the level of Rum1.