title: Activating mutations of N-WASP alter Shigella pathogenesis.
abstract: The pathogenesis of Shigella requires binding to the host protein N-WASP. To examine the roles of structural conformation and phospho-regulation of N-WASP during Shigella pathogenesis, mutant N-WASP constructs predicted to result in a constitutively open conformation (L229P and L232P) or either a phospho-mimicking (Y253E) or phospho-disruptive (Y253F) structure were constructed. Pyrene actin assays demonstrated that the N-WASP L229P and L232P constructs are constitutively active. Despite the increase in actin polymerization seen in vitro, cell lines expressing N-WASP L229P and L232P supported shorter actin tails when infected with Shigella. Shigella actin tails were unchanged in cells expressing N-WASP phospho-regulation mutant proteins. Shigella invasion, intracellular, and intercellular motility were not altered in cells expressing N-WASP L229P or L232P. However, plaque numbers were increased in cells expressing N-WASP L229P and L232P. These data demonstrate that N-WASP structural conformation is an important regulator of Shigella pathogenesis in distinct segments of its lifecycle.
authors.affiliation: Gastrointestinal Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Adamovich
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Nakamura
authors.forename: Austen
authors.initials: A
authors.lastname: Worth
authors.forename: Siobhan
authors.initials: S
authors.lastname: Burns
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Thrasher
authors.forename: John H
authors.initials: JH
authors.lastname: Hartwig
authors.forename: Scott B
authors.initials: SB
authors.lastname: Snapper
mesh_terms: D000199:Actins / Q000378:metabolism; D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D004405:Dysentery, Bacillary / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D017354:Point Mutation; D051381:Rats; D012763:Shigella flexneri / Q000502:physiology*; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000819:agonists* / Q000737:chemistry / Q000235:genetics*
chemical_list: D000199:Actins; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal