Activating mutations of N-WASP alter Shigella pathogenesis

Biochem Biophys Res Commun. 2009 Jul 3;384(3):284-9. doi: 10.1016/j.bbrc.2009.04.050. Epub 2009 Apr 18.

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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Actins / metabolism
  • Amino Acid Substitution
  • Animals
  • Cell Line
  • Dysentery, Bacillary / genetics*
  • Dysentery, Bacillary / metabolism
  • Phosphorylation
  • Point Mutation
  • Rats
  • Shigella flexneri / physiology*
  • Wiskott-Aldrich Syndrome Protein, Neuronal / agonists*
  • Wiskott-Aldrich Syndrome Protein, Neuronal / chemistry
  • Wiskott-Aldrich Syndrome Protein, Neuronal / genetics*

Substances

  • Actins
  • Wiskott-Aldrich Syndrome Protein, Neuronal