The dynamics of zeroth-order ultrasensitivity: A critical phenomenon in cell biology
Qingdao Huang Hong Qian
Discrete & Continuous Dynamical Systems - S 2011, 4(6): 1457-1464 doi: 10.3934/dcdss.2011.4.1457
It is well known since the pioneering work of Goldbeter and Koshland [Proc. Natl. Acad. Sci. USA, vol. 78, pp. 6840-6844 (1981)] that cellular phosphorylation- dephosphorylation cycle (PdPC), catalyzed by kinase and phosphatase under saturated condition with zeroth order enzyme kinetics, exhibits ultrasensitivity, sharp transition. We analyse the dynamics aspects of the zeroth order PdPC kinetics and show a critical slowdown akin to the phase transition in condensed matter physics. We demonstrate that an extremely simple, though somewhat mathematically "singular" model is a faithful representation of the ultrasentivity phenomenon. The simplified mathematical model will be valuable, as a component, in developing complex cellular signaling netowrk theory as well as having a pedagogic value.
keywords: Ultrasensitivity; PdPC; critical phenomenon; cooperative processes.

Year of publication

Related Authors

Related Keywords

[Back to Top]