title: Polar location of the chemoreceptor complex in the Escherichia coli cell.
abstract: The eukaryotic cell exhibits compartmentalization of functions to various membrane-bound organelles and to specific domains within each membrane. The spatial distribution of the membrane chemoreceptors and associated cytoplasmic chemotaxis proteins in Escherichia coli were examined as a prototypic functional aggregate in bacterial cells. Bacterial chemotaxis involves a phospho-relay system brought about by ligand association with a membrane receptor, culminating in a switch in the direction of flagellar rotation. The transduction of the chemotaxis signal is initiated by a chemoreceptor-CheW-CheA ternary complex at the inner membrane. These ternary complexes aggregate predominantly at the cell poles. Polar localization of the cytoplasmic CheA and CheW proteins is dependent on membrane-bound chemoreceptor. Chemoreceptors are not confined to the cell poles in strains lacking both CheA and CheW. The chemoreceptor-CheW binary complex is polarly localized in the absence of CheA, whereas the chemoreceptor-CheA binary complex is not confined to the cell poles in strains lacking CheW. The subcellular localization of the chemotaxis proteins may reflect a general mechanism by which the bacterial cell sequesters different regions of the cell for specialized functions.
authors.affiliation: Department of Developmental Biology, Beckman Center, Stanford University School of Medicine, CA 94305-5427.
authors.forename: J R
authors.initials: JR
authors.lastname: Maddock
authors.forename: L
authors.initials: L
authors.lastname: Shapiro
mesh_terms: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins / Q000032:analysis / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000648:ultrastructure; D002628:Chemoreceptor Cells / Q000502:physiology / Q000648:ultrastructure*; D002630:Chemotactic Factors / Q000378:metabolism; D002633:Chemotaxis / Q000502:physiology; D003593:Cytoplasm / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure*; D029968:Escherichia coli Proteins; D005407:Flagella / Q000502:physiology / Q000648:ultrastructure; D005455:Fluorescent Antibody Technique; D000071677:Histidine Kinase; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism; D000072236:Methyl-Accepting Chemotaxis Proteins; D016253:Microscopy, Immunoelectron; D009004:Monosaccharide Transport Proteins; D010766:Phosphorylation; D011487:Protein Conformation; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D002352:Carrier Proteins; C489103:CheW protein, E coli; D002630:Chemotactic Factors; D029968:Escherichia coli Proteins; D058619:Maltose-Binding Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D009004:Monosaccharide Transport Proteins; C461599:maltose transport system, E coli; C051236:CheW protein, Bacteria; D000071677:Histidine Kinase; C000607608:cheA protein, E coli