Chemical sensing by cell-surface chemoreceptor arrays: the roles of receptor cooperativity and adaptation

TL;DR

This paper explores how receptor cooperativity and adaptation affect the sensitivity limits of chemical gradient sensing in cells, revealing that cooperative and adaptive mechanisms enhance detection accuracy and that receptor layout influences sensing efficiency.

Contribution

It provides a theoretical framework quantifying the impact of receptor cooperativity and adaptation on the limits of chemical gradient sensing in cells.

Findings

Cooperativity lowers sensing limits in certain concentration ranges.

Adaptation broadens the effective concentration range for sensing.

Isotropic receptor layout is optimal for gradient detection.

Abstract

Most sensory cells use cross-membrane chemoreceptors to detect chemical signals in the environment. The biochemical properties and spatial organization of chemoreceptors play important roles in achieving and maintaining sensitivity and accuracy of chemical sensing. Here we investigate the effects of receptor cooperativity and adaptation on the limits of gradient sensing. We study a single cell with aggregated chemoreceptor arrays on the cell surface and derive general formula to the limits for gradient sensing from the uncertainty of instantaneous receptor activity. In comparison to independent receptors, we find that cooperativity by non-adaptative receptors could significantly lower the sensing limit in a chemical concentration range determined by the biochemical properties of ligand-receptor binding and ligand-induced receptor activity. Cooperativity by adaptative receptors are beneficial to gradient sensing within a broad range of background concentrations. Our results also show that isotropic receptor aggregate layout on the cell surface represents an optimal configuration to gradient sensing.