title: Chemodetection in fluctuating environments: receptor coupling, buffering, and antagonism.
abstract: Variability in the chemical composition of the extracellular environment can significantly degrade the ability of cells to detect rare cognate ligands. Using concepts from statistical detection theory, we formalize the generic problem of detection of small concentrations of ligands in a fluctuating background of biochemically similar ligands binding to the same receptors. We discover that in contrast with expectations arising from considerations of signal amplification, inhibitory interactions between receptors can improve detection performance in the presence of substantial environmental variability, providing an adaptive interpretation to the phenomenon of ligand antagonism. Our results suggest that the structure of signaling pathways responsible for chemodetection in fluctuating and heterogeneous environments might be optimized with respect to the statistics and dynamics of environmental composition. The developed formalism stresses the importance of characterizing nonspecific interactions to understand function in signaling pathways.
authors.affiliation: Physics Department, McGill University, Montréal, QC, Canada H3A 2T8.
authors.forename: Jean-Benoît
authors.initials: JB
authors.lastname: Lalanne
authors.affiliation: Physics Department, McGill University, Montréal, QC, Canada H3A 2T8 paulf@physics.mcgill.ca.
authors.forename: Paul
authors.initials: P
authors.lastname: François
mesh_terms: D003198:Computer Simulation; D004777:Environment; D008024:Ligands; D008954:Models, Biological; D020239:Receptor Cross-Talk / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D008024:Ligands; D011956:Receptors, Cell Surface
keywords: chemodetection; fluctuating environment; immune recognition; nonspecific interactions; statistical decision