Inter-receptor communication through arrays of bacterial chemoreceptors

• Published in: Nature (London) 2002-01, Vol.415 (6867), p.81-84
• Main Authors: Kiessling, Laura L, Gestwicki, Jason E
• Format: Article
• Language: English
• Subjects: Bacteria; Bacterial Proteins - metabolism; Bacteriology; Biochemistry; Biological and medical sciences; Cell receptors; Chemoreceptors; Chemotactic Factors - pharmacology; Chemotaxis - drug effects; DNA microarrays; Dose-Response Relationship, Drug; E coli; Escherichia coli; Escherichia coli - cytology; Escherichia coli - drug effects; Escherichia coli - metabolism; Escherichia coli Proteins - metabolism; Fundamental and applied biological sciences. Psychology; Genetic aspects; Humanities and Social Sciences; letter; Ligands; Membrane Proteins; Microbiology; Motility, taxis; multidisciplinary; Physiological aspects; Proteins; Receptors, Amino Acid - metabolism; Receptors, Cell Surface - metabolism; Science; Science (multidisciplinary); Serine - pharmacology; Signal Transduction - drug effects
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/415081a

The sensing mechanisms of chemotactic bacteria allow them to respond sensitively to stimuli. Escherichia coli, for example, respond to changes in chemoattractant concentration of less than 10% over a range spanning six orders of magnitude. Sensitivity over this range depends on a nonlinear relationship between ligand concentration and output response. At low ligand concentrations, substantial amplification of the chemotactic signal is required; however, the mechanism responsible for this amplification remains unclear. Here we demonstrate that inter-receptor communication within a lattice acts to amplify and integrate sensory information. Synthetic multivalent ligands that interact through the low-abundance, galactose-sensing receptor Trg stabilize large clusters of chemoreceptors and markedly enhance signal output from these enforced clusters. On treatment with multivalent ligands, the response to the attractant serine is amplified by at least 100-fold. This amplification requires a full complement of chemoreceptors; deletion of the aspartate (Tar) or dipeptide (Tap) receptors diminishes the amplification of the serine response. These results demonstrate that the entire array is involved in sensing. This mode of information exchange has general implications for the processing of signals by cellular receptors.