# Induction kinetics of a conditional pH stress response system in Escherichia coli Source: [Induction kinetics of a conditional pH stress response system in Escherichia coli]() Collection index: [llms.txt]() Data updated: 2025-10-25T18:52:48.052Z Authors: Georg Fritz, Christiane Koller, Korinna Burdack, Larissa Tetsch, Ina Haneburger, Kirsten Jung, Ulrich Gerland Published: 2010-09-16T12:15:50.000Z ## Abstract The analysis of stress response systems in microorganisms can reveal molecular strategies for regulatory control and adaptation. Here, we focus on the Cad module, a subsystem of E. coli's response to acidic stress, which is conditionally activated at low pH only when lysine is available. When expressed, the Cad system counteracts the elevated H+ concentration by converting lysine to cadaverine under the consumption of H+, and exporting cadaverine in exchange for external lysine. Surprisingly, the cad operon displays a transient response, even when the conditions for its induction persist. To quantitatively characterize the regulation of the Cad module, we have experimentally recorded and theoretically modeled the dynamics of important system variables. We establish a quantitative model that adequately describes and predicts the transient expression behavior for various initial conditions. Our quantitative analysis of the Cad system supports a negative feedback by external cadaverine as the origin of the transient response. Furthermore, the analysis puts causal constraints on the precise mechanism of signal transduction via the regulatory protein CadC. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()