title: Capping of actin filaments by vinculin activated by the Shigella IpaA carboxyl-terminal domain.
abstract: Shigella, the causative agent of bacillary dysentery, invades epithelial cells. Upon bacterial-cell contact, the type III bacterial effector IpaA binds to the cytoskeletal protein vinculin to promote actin reorganization required for efficient bacterial uptake. We show that the last 74 C-terminal residues of IpaA (A559) bind to human vinculin (HV) and promotes its association with actin filaments. Polymerisation experiments demonstrated that A559 was sufficient to induce HV-dependent partial capping of the barbed ends of actin filaments. These results suggest that IpaA regulates actin polymerisation/depolymerisation at sites of Shigella invasion by modulating the barbed end capping activity of vinculin.
authors.affiliation: Unité de Pathogénie Microbienne Moléculaire, Inserm U786, Institut Pasteur, 75724 Paris Cedex 15, France.
authors.forename: Nalini
authors.initials: N
authors.lastname: Ramarao
authors.forename: Christophe
authors.initials: C
authors.lastname: Le Clainche
authors.forename: Tina
authors.initials: T
authors.lastname: Izard
authors.forename: Raphaëlle
authors.initials: R
authors.lastname: Bourdet-Sicard
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ageron
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Sansonetti
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Carlier
authors.forename: Guy
authors.initials: G
authors.lastname: Tran Van Nhieu
mesh_terms: D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D001704:Biopolymers / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D012760:Shigella / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D016596:Vinculin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D000199:Actins; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001704:Biopolymers; C063664:IpaA protein, Shigella flexneri; D011994:Recombinant Proteins; C488955:VCL protein, human; D016596:Vinculin