RRC ID 4961
Author Greenfield D, McEvoy AL, Shroff H, Crooks GE, Wingreen NS, Betzig E, Liphardt J.
Title Self-organization of the Escherichia coli chemotaxis network imaged with super-resolution light microscopy.
Journal PLoS Biol.
Abstract The Escherichia coli chemotaxis network is a model system for biological signal processing. In E. coli, transmembrane receptors responsible for signal transduction assemble into large clusters containing several thousand proteins. These sensory clusters have been observed at cell poles and future division sites. Despite extensive study, it remains unclear how chemotaxis clusters form, what controls cluster size and density, and how the cellular location of clusters is robustly maintained in growing and dividing cells. Here, we use photoactivated localization microscopy (PALM) to map the cellular locations of three proteins central to bacterial chemotaxis (the Tar receptor, CheY, and CheW) with a precision of 15 nm. We find that cluster sizes are approximately exponentially distributed, with no characteristic cluster size. One-third of Tar receptors are part of smaller lateral clusters and not of the large polar clusters. Analysis of the relative cellular locations of 1.1 million individual proteins (from 326 cells) suggests that clusters form via stochastic self-assembly. The super-resolution PALM maps of E. coli receptors support the notion that stochastic self-assembly can create and maintain approximately periodic structures in biological membranes, without direct cytoskeletal involvement or active transport.
Volume 7(6)
Pages e1000137
Published 2009-6-16
DOI 10.1371/journal.pbio.1000137
PMID 19547746
PMC PMC2691949
MeSH Bacterial Proteins / biosynthesis Chemoreceptor Cells Chemotaxis* Escherichia coli / cytology Escherichia coli / metabolism* Escherichia coli Proteins / biosynthesis Membrane Proteins / biosynthesis Methyl-Accepting Chemotaxis Proteins Microscopy Models, Biological Receptors, Cell Surface / metabolism Recombinant Fusion Proteins / biosynthesis Signal Transduction Stochastic Processes
IF 8.386
Times Cited 190
Prokaryotes E. coli JW1875 JW1876