The role of cooperative binding on noise expression

TL;DR

This paper investigates how cooperative binding influences noise in gene expression, showing that increased interaction energy amplifies fluctuations and enabling differentiation between two cooperative mechanisms.

Contribution

It introduces a stochastic model for gene regulation with multiple binding sites to analyze the impact of cooperativity on gene expression noise.

Findings

Higher interaction energy increases the Hill coefficient and noise level.

The model distinguishes between two cooperative binding mechanisms.

Cooperativity amplifies intrinsic fluctuations in gene expression.

Abstract

The origin of stochastic fluctuations in gene expression has received considerable attention recently. Fluctuations in gene expression are particularly pronounced in cellular systems because of the small copy number of species undergoing transitions between discrete chemical states and the small size of biological compartments. In this paper, we propose a stochastic model for gene expression regulation including several binding sites, considering elementary reactions only. The model is used to investigate the role of cooperativity on the intrinsic fluctuations of gene expression, by means of master equation formalism. We found that the Hill coefficient and the level of noise increases as the interaction energy between activators increases. Additionally, we show that the model allows to distinguish between two cooperative binding mechanisms.