Negative Feedback and Physical Limits of Genes

TL;DR

This paper analyzes how negative feedback in genes affects their response speed and noise levels, showing that auto-repressed genes are faster and less noisy than simple genes under certain conditions.

Contribution

It provides a comparative analysis of auto-repressed versus simple genes, highlighting conditions where negative feedback improves gene response and noise characteristics.

Findings

Negative feedback reduces gene switching times with non-zero leak expression.

Auto-repressed genes have lower noise at low leak expression rates.

Auto-repressed genes are faster and less noisy than simple genes under specific conditions.

Abstract

This paper compares the auto-repressed gene to a simple one (a gene without auto-regulation) in terms of response time and output noise under the assumption of fixed metabolic cost. The analysis shows that, in the case of non-vanishing leak expression rate, the negative feedback reduces both the switching on and switching off times of a gene. The noise of the auto-repressed gene will be lower than the one of the simple gene only for low leak expression rates. Summing up, for low, but non-vanishing leak expression rates, the auto-repressed gene is both faster and less noisier compared to the simple one.