Cooperative binding and noise expression

L. DIAMBRA

Cambridge

Congreso; Noise in Life 2009; 2009

SIGNET and Biotechnology and Biological Sciences Research Council

All chemical reactions have intrinsic fluctuations that are inversely proportional to thesystem size. Such fluctuations are particularly pronounced in gene expression. We proposea stochastic model for gene expression regulation including several binding sites,considering elementary reactions only. The model is used to investigate the role ofcooperativity on the intrinsic fluctuations of gene expression, by means of master equationformalism and computer simulation. Our model predicts that the level of noise increases asthe interaction energy between activators increases. Furthermore, the model allows todistinguish between two cooperative binding mechanisms. While the mean expression levelsare not affected differently by what mechanism is acting, they induce very differentfluctuation levels in the expression.