Variable sizes of Escherichia coli chemoreceptor signaling teams.
Like many sensory receptors, bacterial chemotaxis receptors form clusters. In bacteria, large-scale clusters are subdivided into signaling teams that act as 'antennas' allowing detection of ligands with remarkable sensitivity. The range of sensitivity is greatly extended by adaptation of receptors to changes in concentrations through covalent modification. However, surprisingly little is known about the sizes of receptor signaling teams. Here, we combine measurements of the signaling response, obtained from in vivo fluorescence resonance energy transfer, with the statistical method of principal component analysis, to quantify the size of signaling teams within the framework of the previously successful Monod-Wyman-Changeux model. We find that size of signaling teams increases 2- to 3-fold with receptor modification, indicating an additional, previously unrecognized level of adaptation of the chemotaxis network. This variation of signaling-team size shows that receptor cooperativity is dynamic and likely optimized for sensing noisy ligand concentrations.
Endres
Robert G
RG
Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA.
Oleksiuk
Olga
O
Hansen
Clinton H
CH
Meir
Yigal
Y
Sourjik
Victor
V
Wingreen
Ned S
NS
D001224:Aspartic Acid / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D002628:Chemoreceptor Cells / Q000378:metabolism*; D002633:Chemotaxis; D003198:Computer Simulation; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D008780:Methyltransferases / Q000378:metabolism; D008954:Models, Biological; D025341:Principal Component Analysis; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D015398:Signal Transduction
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008024:Ligands; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C057331:Tar protein, E coli; C069656:CheB protein, Bacteria; D001224:Aspartic Acid; C513923:CheR protein, E coli; D008780:Methyltransferases