6533b86cfe1ef96bd12c816d
RESEARCH PRODUCT
Pore-forming toxins activate MAPK p38 by causing loss of cellular potassium.
Sucharit BhakdiClaudia NeukirchWiesia BobkiewiczIngo CibisSilvia WeisFatima BoukhalloukNicole KloftTim BuschMatthias Husmannsubject
Pore Forming Cytotoxic ProteinsOsmotic shockp38 mitogen-activated protein kinasesBacterial ToxinsBiophysicsBiologyHemolysin ProteinsBiochemistryp38 Mitogen-Activated Protein KinasesCell LineCell membraneHemolysin ProteinsmedicineHumansPhosphorylationMolecular BiologyPore-forming toxinEscherichia coli ProteinsCell MembraneHemolysinEpithelial CellsCell BiologyCell biologyEnzyme Activationmedicine.anatomical_structureBiochemistryPotassiumStreptolysinCalciumCytolysindescription
Mitogen activated protein kinase (MAPK) p38 has emerged as a survival protein in cells that are attacked by bacterial toxins forming small membrane pores. Activation of p38 by pore forming toxins (PFT) has been attributed to osmotic stress, but here we show that loss of K+ is likely to be the critical parameter. Several lines of evidence support this conclusion: first, osmoprotection did not prevent p38-phosphorylation in alpha-toxin-loaded cells. Second, treatment of cells with a K+ ionophore, or simple incubation in K+-free medium sufficed to cause robust p38-phosphorylation. Third, media containing high [K+] prevented p38-activation by Staphylococcus aureus alpha-toxin, Vibrio cholerae cytolysin (VCC), Streptolysin O (SLO), or Escherichia coli hemolysin (HlyA), but did not impair activation by H2O2. Fourth, potential roles of LPS, TLR4, or calcium-influx were ruled out. Therefore, we propose that PFT trigger the p38 MAPK-pathway by causing loss of cellular K+.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-08-01 | Biochemical and biophysical research communications |