title: Molecular basis of actin reorganization promoted by binding of enterohaemorrhagic Escherichia coli EspB to alpha-catenin.
abstract: EspB is a multifunctional protein associated with the type III secretion system of enterohaemorrhagic Escherichia coli, and interacts with various biomolecules including alpha-catenin in the host cell. The binding of EspB to alpha-catenin is thought be involved in actin reorganization during bacterial infection, although the precise mechanism of this phenomenon is still unclear. Recent research shows that dimerization of alpha-catenin dissociates it from E-cadherin/beta-catenin/alpha-catenin complexes, and that the dimer suppresses Arp2/3-mediated actin branching or polymerization. These results inspired us to evaluate the effect of EspB on the functions of alpha-catenin. Based on a series of in vitro biochemical approaches, including pull-down, co-sedimentation and pyrene-actin polymerization assays combined with transmission electron microscopy, we conclude that EspB promotes all the functions of dimeric alpha-catenin described above. These results clarified the molecular basis of reorganization of actin filaments during infection with enterohaemorrhagic Escherichia coli.
authors.affiliation: Department of Developmental Infectious Diseases, Research Institute, Osaka Medical Center for Maternal and Child Health, Japan.
authors.forename: Mitsuhide
authors.initials: M
authors.lastname: Hamaguchi
authors.forename: Daizo
authors.initials: D
authors.lastname: Hamada
authors.forename: Kayo N
authors.initials: KN
authors.lastname: Suzuki
authors.forename: Ikuhiro
authors.initials: I
authors.lastname: Sakata
authors.forename: Itaru
authors.initials: I
authors.lastname: Yanagihara
mesh_terms: D000199:Actins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001665:Binding Sites; D015820:Cadherins / Q000737:chemistry / Q000378:metabolism; D054324:Enterohemorrhagic Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D006090:Gram-Negative Bacteria / Q000378:metabolism; D007700:Kinetics; D008854:Microscopy, Electron; D011485:Protein Binding; D016596:Vinculin / Q000737:chemistry / Q000378:metabolism; D051178:alpha Catenin / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000199:Actins; D001425:Bacterial Outer Membrane Proteins; D015820:Cadherins; C087863:EaeB protein, E coli; D029968:Escherichia coli Proteins; D051178:alpha Catenin; D016596:Vinculin