title: Robust mitotic entry is ensured by a latching switch.
abstract: Cell cycle events are driven by Cyclin dependent kinases (CDKs) and by their counter-acting phosphatases. Activation of the Cdk1:Cyclin B complex during mitotic entry is controlled by the Wee1/Myt1 inhibitory kinases and by Cdc25 activatory phosphatase, which are themselves regulated by Cdk1:Cyclin B within two positive circuits. Impairing these two feedbacks with chemical inhibitors induces a transient entry into M phase referred to as mitotic collapse. The pathology of mitotic collapse reveals that the positive circuits play a significant role in maintaining the M phase state. To better understand the function of these feedback loops during G2/M transition, we propose a simple model for mitotic entry in mammalian cells including spatial control over Greatwall kinase phosphorylation. After parameter calibration, the model is able to recapture the complex and non-intuitive molecular dynamics reported by Potapova et al. (Potapova et al., 2011). Moreover, it predicts the temporal patterns of other mitotic regulators which have not yet been experimentally tested and suggests a general design principle of cell cycle control: latching switches buffer the cellular stresses which accompany cell cycle processes to ensure that the transitions are smooth and robust.
authors.affiliation: Oxford Centre for Integrative Systems Biology, Department of Biochemistry , South Parks Road, Oxford OX1 3QU , UK.
authors.forename: Chloe
authors.initials: C
authors.lastname: Tuck
authors.forename: Tongli
authors.initials: T
authors.lastname: Zhang
authors.forename: Tamara
authors.initials: T
authors.lastname: Potapova
authors.forename: Marcos
authors.initials: M
authors.lastname: Malumbres
authors.forename: Béla
authors.initials: B
authors.lastname: Novák
keywords: Cell cycle; G2/M transition; Greatwall kinase; Mitotic collapse; Mitotic entry; Spatial control of mitosis