Optimal Frequency in Second Messenger Signaling Quantifying cAMP Information Transmission in Bacteria

TL;DR

This study engineered a controlled cAMP signaling system in bacteria to quantify its information transmission capacity, revealing an optimal signaling frequency that maximizes information transfer and provides insights into bacterial communication strategies.

Contribution

We developed a method to precisely control and measure bacterial cAMP signaling, quantifying its maximum information transmission rate and identifying an optimal signaling frequency.

Findings

Maximum information transmission rate of 40 bits/h.

Optimal signaling frequency correlates with cAMP degradation kinetics.

Two-state encoding scheme enables efficient information transfer.

Abstract

Bacterial second messengers are crucial for transmitting environmental information to cellular responses. However, quantifying their information transmission capacity remains challenging. Here, we engineer an isolated cAMP signaling channel in Pseudomonas aeruginosa using targeted gene knockouts, optogenetics, and a fluorescent cAMP probe. This design allows precise optical control and real-time monitoring of cAMP dynamics. By integrating experimental data with information theory, we reveal an optimal frequency for light-mediated cAMP signaling that maximizes information transmission, reaching about 40 bits/h. This rate correlates strongly with cAMP degradation kinetics and employs a two-state encoding scheme. Our findings suggest a mechanism for fine-tuned regulation of multiple genes through temporal encoding of second messenger signals, providing new insights into bacterial adaptation strategies. This approach offers a framework for quantifying information processing in cellular signaling systems.