Transcriptional leakage versus noise: A simple mechanism of conversion between binary and graded response in autoregulated genes

TL;DR

This paper investigates how transcriptional leakage and noise influence gene response types, revealing that noise promotes binary responses while leakage favors graded responses, offering insights into evolutionary gene regulation tuning.

Contribution

It demonstrates how transcriptional leakage and noise have opposite effects on gene response types in autoregulated genes, highlighting a simple mechanism for evolutionary tuning.

Findings

Increased noise converts graded responses to binary.

Increased leakage converts binary responses to graded.

Leaky expression may facilitate evolutionary tuning of gene responses.

Abstract

We study the response of an autoregulated gene to a range of concentrations of signal molecules. We show that transcriptional leakage and noise due to translational bursting have the opposite effects. In a positively autoregulated gene, increasing the noise converts the response from graded to binary, while increasing the leakage converts the response from binary to graded. Our findings support the hypothesis that, being a common phenomenon, leaky expression may be a relatively easy way for evolutionary tuning of the type of gene response without changing the type of regulation from positive to negative.