title: Recruitment and membrane interactions of host cell proteins during attachment of enteropathogenic and enterohaemorrhagic Escherichia coli.
abstract: EPEC (enteropathogenic Escherichia coli) and EHEC (enterohaemorrhagic Escherichia coli) are attaching and effacing pathogens frequently associated with infectious diarrhoea. EPEC and EHEC use a T3SS (type III secretion system) to translocate effectors that subvert different cellular processes to sustain colonization and multiplication. The eukaryotic proteins NHERF2 (Na(+)/H(+) exchanger regulatory factor 2) and AnxA2 (annexin A2), which are involved in regulation of intestinal ion channels, are recruited to the bacterial attachment sites. Using a stable HeLa-NHERF2 cell line, we found partial co-localization of AnxA2 and NHERF2; in EPEC-infected cells, AnxA2 and NHERF2 were extensively recruited to the site of bacterial attachment. We confirmed that NHERF2 dimerizes and found that NHERF2 interacts with AnxA2. Moreover, we found that AnxA2 also binds both the N- and C-terminal domains of the bacterial effector Tir through its C-terminal domain. Immunofluorescence of HeLa cells infected with EPEC showed that AnxA2 is recruited to the site of bacterial attachment in a Tir-dependent manner, but independently of Tir-induced actin polymerization. Our results suggest that AnxA2 and NHERF2 form a scaffold complex that links adjacent Tir molecules at the plasma membrane forming a lattice that could be involved in retention and dissemination of other effectors at the bacterial attachment site.
authors.affiliation: Centre for Molecular Microbiology and Infection, Division of Cell and Molecular Biology, Imperial College London, London SW7 2AZ, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Munera
authors.forename: Eric
authors.initials: E
authors.lastname: Martinez
authors.forename: Svetlana
authors.initials: S
authors.lastname: Varyukhina
authors.forename: Arvind
authors.initials: A
authors.lastname: Mahajan
authors.forename: Jesus
authors.initials: J
authors.lastname: Ayala-Sanmartin
authors.forename: Gad
authors.initials: G
authors.lastname: Frankel
mesh_terms: D017306:Annexin A2 / Q000235:genetics / Q000502:physiology*; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology / Q000503:physiopathology; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D054308:Enteropathogenic Escherichia coli / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000503:physiopathology; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D006367:HeLa Cells; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D054730:Protein Interaction Domains and Motifs; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: C472822:ANXA2 protein, human; D017306:Annexin A2; D017931:DNA Primers; D029968:Escherichia coli Proteins; D010750:Phosphoproteins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D017923:Sodium-Hydrogen Exchangers; C109287:Tir protein, E coli; C093376:sodium-hydrogen exchanger regulatory factor