BIOPHYSICAL THEORY AND MODELING |
Stable stochastic dynamics in yeast cell cycle
Yurie Okabe 1 and Masaki Sasai 1*
1 Nagoya University
* To whom correspondence should be addressed. E-mail: sasai{at}cse.nagoya-u.ac.jp.
Submitted on April 2, 2007
Revised on June 6, 2007
Accepted on 26 July 2007
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Abstract |
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Chemical reactions in cell are subject to intense stochastic fluctuations. An important question is how the fundamental physiological behavior of cell is kept stable against those noisy perturbations. In this paper a stochastic model of cell cycle of budding yeast is constructed to analyze the effects of noise on the cell cycle oscillation. The model predicts intense noise in levels of mRNAs and proteins, and the simulated protein levels explain the observed statistical tendency of noise in populations of synchronous and asynchronous cells. In spite of intense noise in levels of proteins and mRNAs, cell cycle is stable enough to bring the largely perturbed cells back to the physiological cyclic oscillation. The model shows that consecutively appearing fixed points are the origin of this stability of cell cycle.
Key Words:
cell cycle, extrinsic and intrinsic noises, stochastic dynamics
