Dynamics of cooperativity in chemical sensing among cell-surface receptors

TL;DR

This paper investigates how receptor cooperativity affects sensing precision in cell-surface receptors, revealing that independent receptors often provide the optimal signal-to-noise ratio despite cooperative interactions.

Contribution

It introduces a simple Ising-type model to analyze receptor cooperativity's impact on sensing accuracy, showing that independence maximizes the signal-to-noise ratio.

Findings

Optimal sensing occurs with independent receptors.

Cooperative interactions can increase intrinsic noise.

Receptor conformational dynamics influence sensing precision.

Abstract

Cooperative interactions among sensory receptors provide a general mechanism to increase the sensitivity of signal transduction. In particular, bacterial chemotaxis receptors interact cooperatively to produce an ultrasensitive response to chemoeffector concentrations. However, cooperativity between receptors in large macromolecular complexes is necessarily based on local interactions and consequently is fundamentally connected to slowing of receptor conformational dynamics, which increases intrinsic noise. Therefore, it is not clear whether or under what conditions cooperativity actually increases the precision of the concentration measurement. We explictly calculate the signal-to-noise ratio (SNR) for sensing a concentration change using a simple, Ising-type model of receptor-receptor interactions, generalized via scaling arguments, and find that the optimal SNR is always achieved by independent receptors.