title: BipA: a tyrosine-phosphorylated GTPase that mediates interactions between enteropathogenic Escherichia coli (EPEC) and epithelial cells.
abstract: We report the functional characterization of BipA, a GTPase that undergoes tyrosine phosphorylation in an enteropathogenic Escherichia coli (EPEC) strain. BipA mutants adhere to cultured epithelial cells but fail to trigger the characteristic cytoskeletal rearrangements found in cells infected with wild-type EPEC. In contrast, increased expression of BipA enhances actin remodelling and results in the hyperformation of pseudopods. BipA appears to be the first example of a new class of virulence regulator, as it also controls flagella-mediated cell motility and resistance to the antibacterial effects of a human host defence protein. Its striking sequence similarity to ribosome-binding elongation factors suggests that it uses a novel mechanism to modulate gene expression.
authors.affiliation: Department of Biochemistry, University of Southampton, UK.
authors.forename: M
authors.initials: M
authors.lastname: Farris
authors.forename: A
authors.initials: A
authors.lastname: Grant
authors.forename: T B
authors.initials: TB
authors.lastname: Richardson
authors.forename: C D
authors.initials: CD
authors.lastname: O'Connor
mesh_terms: D000595:Amino Acid Sequence; D001422:Bacterial Adhesion / Q000235:genetics; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology; D001426:Bacterial Proteins / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D005408:Flagellin / Q000032:analysis; D020558:GTP Phosphohydrolases / Q000737:chemistry / Q000502:physiology*; D015964:Gene Expression Regulation, Bacterial; D006367:HeLa Cells; D006801:Humans; D015151:Immunoblotting; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D016415:Sequence Alignment; D014443:Tyrosine / Q000378:metabolism; D014774:Virulence
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D005408:Flagellin; D014443:Tyrosine; D020558:GTP Phosphohydrolases