Anaplasma phagocytophilum AptA modulates Erk1/2 signalling

Cell Microbiol. 2011 Jan;13(1):47-61. doi: 10.1111/j.1462-5822.2010.01516.x. Epub 2010 Aug 27.


Anaplasma phagocytophilum causes human granulocytic anaplasmosis, one of the most common tick-borne diseases in North America. This unusual obligate intracellular pathogen selectively persists within polymorphonuclear leucocytes. In this study, using the yeast surrogate model we identified an A. phagocytophilum virulence protein, AptA (A. phagocytophilum toxin A), that activates mammalian Erk1/2 mitogen-activated protein kinase. This activation is important for A. phagocytophilum survival within human neutrophils. AptA interacts with the intermediate filament protein vimentin, which is essential for A. phagocytophilum-induced Erk1/2 activation and infection. A. phagocytophilum infection reorganizes vimentin around the bacterial inclusion, thereby contributing to intracellular survival. These observations reveal a major role for the bacterial protein, AptA, and the host protein, vimentin, in the activation of Erk1/2 during A. phagocytophilum infection.

Publication types

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

MeSH terms

  • Anaplasma phagocytophilum / pathogenicity*
  • Bacterial Proteins / metabolism*
  • Cell Line
  • Humans
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Neutrophils / microbiology
  • Signal Transduction*
  • Vimentin / metabolism
  • Virulence Factors / metabolism*


  • Bacterial Proteins
  • Vimentin
  • Virulence Factors
  • MAPK1 protein, human
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3