6533b828fe1ef96bd1288e97
RESEARCH PRODUCT
Rho protein inhibition blocks protein kinase C translocation and activation.
Joachim SeyboldStefan HippenstielChristoph Von Eichel-streiberThomas KratzNorbert SuttorpMatthias Krüllsubject
LipopolysaccharidesRHOASwineBiophysicsClostridium difficile toxin ABronchiCell Cycle ProteinsGTPaseCDC42PKC alphaBiochemistryGTP-Binding ProteinsRHO protein GDP dissociation inhibitorAnimalsHumanscdc42 GTP-Binding ProteinMolecular BiologyProtein kinase CCells CulturedProtein Kinase CbiologyEpithelial CellsCell BiologyMolecular biologyCell biologyEnzyme ActivationCdc42 GTP-Binding Proteinbiology.proteinras ProteinsTetradecanoylphorbol AcetateEndothelium VascularrhoA GTP-Binding Proteindescription
Small GTP-binding proteins of the Ras and Rho family participate in various important signalling pathways. Large clostridial cytotoxins inactivate GTPases by UDP-glucosylation. Using Clostridium difficile toxin B-10463 (TcdB) for inactivation of Rho proteins (RhoA/Rac/Cdc42) and Clostridium sordellii lethal toxin-1522 (TcsL) for inactivation of Ras-proteins (Ras/Rac/Ral, Rap) the role of these GTPases in protein kinase C (PKC) stimulation was studied. Phorbol-myristate-acetate (PMA) induced a rapid PKC translocation to and activation in the particulate cell fraction as determined by PKC-activity measurements and Western blots for PKC alpha. These effects were blocked by TcdB inhibiting Rho proteins in endothelial cells, but not in TcsL-treated cells (i.e., cells without Ras activity), suggesting that Rho GTPases (RhoA and/or Cdc42) are the most likely GTP-binding proteins responsible for PKC activation. The Rho requirement for PKC activation/translocation was also verified for human epithelial cells and for lipopolysaccharide-stimulated endothelial cells. In summary, the data presented indicate that Rho protein inhibition blocked PKC translocation/activation in endothelial and epithelial cells.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1998-05-20 | Biochemical and biophysical research communications |