Adapter Protein SH2-Bβ Stimulates Actin-Based Motility of Listeria monocytogenes in a Vasodilator-Stimulated Phosphoprotein (VASP)-Dependent Fashion Article (Web of Science)

abstract

  • ABSTRACT SH2-Bβ (Src homology 2 Bβ) is an adapter protein that is required for maximal growth hormone-dependent actin reorganization in membrane ruffling and cell motility. Here we show that SH2-Bβ is also required for maximal actin-based motility of Listeria monocytogenes . SH2-Bβ localizes to Listeria -induced actin tails and increases the rate of bacterial propulsion in infected cells and in cell extracts. Furthermore, Listeria motility is decreased in mouse embryo fibroblasts from SH2-B −/− mice. Both recruitment of SH2-Bβ to Listeria and SH2-Bβ stimulation of actin-based propulsion require the vasodilator-stimulated phosphoprotein (VASP), which binds ActA at the surfaces of Listeria cells and enhances bacterial actin-based motility. SH2-Bβ enhances actin-based movement of ActA-coated beads in a biomimetic actin-based motility assay, provided that VASP is present. In vitro binding assays show that SH2-Bβ binds ActA but not VASP; however, binding to ActA is greater in the presence of VASP. Because VASP also plays an essential regulatory role in actin-based processes in eukaryotic cells, the present results provide mechanistic insight into the functions of both SH2-Bβ and VASP in motility and also increase our understanding of the fundamental mechanism by which Listeria spreads.

authors

  • Diakonova, Maria
  • Helfer, Emmanuele
  • Seveau, Stephanie
  • Swanson, Joel A.
  • Kocks, Christine
  • Rui, Liangyou
  • Carlier, Marie-France
  • Carter-Su, Christin

publication date

  • 2007

published in

number of pages

  • 12

start page

  • 3581

end page

  • 3593

volume

  • 75

issue

  • 7