Actin-based motility of vaccinia virus mimics receptor tyrosine kinase signalling

Nature. 1999 Oct 28;401(6756):926-9. doi: 10.1038/44860.


Studies of the actin-based motility of the intracellular pathogens Listeria monocytogenes and Shigella flexneri have provided important insight into the events occurring at the leading edges of motile cells. Like the bacteria Listeria and Shigella, vaccinia virus, a relative of the causative agent of smallpox, uses actin-based motility to spread between cells. In contrast to Listeria or Shigella, the actin-based motility of vaccinia is dependent on an unknown phosphotyrosine protein, but the underlying mechanism remains obscure. Here we show that phosphorylation of tyrosine 112 in the viral protein A36R by Src-family kinases is essential for the actin-based motility of vaccinia. Tyrosine phosphorylation of A36R results in a direct interaction with the adaptor protein Nck and the recruitment of the Ena/VASP family member N-WASP to the site of actin assembly. We also show that Nck and N-WASP are essential for the actin-based motility of vaccinia virus. We suggest that vaccinia virus spreads by mimicking the signalling pathways that are normally involved in actin polymerization at the plasma membrane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / physiology*
  • Animals
  • HeLa Cells
  • Humans
  • Lectins / physiology
  • Lectins, C-Type*
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology
  • Mice
  • Molecular Mimicry
  • Phosphorylation
  • Point Mutation
  • Receptor Protein-Tyrosine Kinases / physiology*
  • Receptors, Cell Surface / physiology
  • Signal Transduction*
  • Tyrosine / metabolism
  • Vaccinia virus / genetics
  • Vaccinia virus / physiology*
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / physiology
  • Viral Structural Proteins / genetics
  • Viral Structural Proteins / physiology
  • src-Family Kinases / physiology


  • A36R protein, Vaccinia virus
  • Actins
  • Clec4n protein, mouse
  • Lectins
  • Lectins, C-Type
  • Membrane Proteins
  • Receptors, Cell Surface
  • Viral Envelope Proteins
  • Viral Structural Proteins
  • Tyrosine
  • Receptor Protein-Tyrosine Kinases
  • src-Family Kinases