0000000000180888

AUTHOR

Ingo Just

showing 6 related works from this author

Inhibition of FcεRI-mediated Activation of Rat Basophilic Leukemia Cells by Clostridium difficile Toxin B (Monoglucosyltransferase)

1996

Abstract Treatment of rat basophilic leukemia (RBL) 2H3-hm1 cells with Clostridium difficile toxin B (2 ng/ml), which reportedly depolymerizes the actin cytoskeleton, blocked [3H]serotonin release induced by 2,4-dinitrophenyl-bovine serum albumin, carbachol, mastoparan, and reduced ionophore A23187-stimulated degranulation by about 55-60%. In lysates of RBL cells, toxin B 14C-glucosylated two major and one minor protein. By using two-dimensional gel electrophoresis and immunoblotting, RhoA and Cdc42 were identified as protein substrates of toxin B. In contrast to toxin B, Clostridium botulinum transferase C3 that selectively inactivates RhoA by ADP-ribosylation did not inhibit degranulation…

SerotoninRHOABacterial ToxinsClostridium difficile toxin AWasp VenomsClostridium difficile toxin BBiologyCytoplasmic GranulesTritiummedicine.disease_causeBiochemistryCell LinePhosphatidylinositol 3-KinasesBacterial ProteinsTumor Cells CulturedmedicineAnimalsEnzyme InhibitorsMolecular BiologyCalcimycinAdenosine Diphosphate RiboseClostridioides difficileReceptors IgEToxinDegranulationSerum Albumin BovineCell BiologyActin cytoskeletonMolecular biologyRatsAndrostadienesKineticsPhosphotransferases (Alcohol Group Acceptor)Leukemia Basophilic AcuteBiochemistryGlucosyltransferasesMastoparanbiology.proteinIntercellular Signaling Peptides and ProteinsClostridium botulinumCarbacholCattle24-DinitrophenolPeptidesWortmanninDinitrophenolsJournal of Biological Chemistry
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A role for Rho in receptor- and G protein-stimulated phospholipase C Reduction in phosphatidylinositol 4,5-bisphosphate by Clostridium difficile toxi…

1996

Receptors coupled to heterotrimeric guanine nucleotide-binding proteins (G proteins) activate phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2)-hydrolyzing phospholipase C (PLC) enzymes by activated alpha of free beta gamma subunits of the relevant G proteins. To study whether low molecular weight G proteins of the Rho family are involved in receptor signaling to PLC, we examined the effect of Clostridium difficile toxin B, which glucosylates and thereby inactivates Rho proteins, on the regulation of PLC activity in human embryonic kidney (HEK) cells stably expressing the m3 muscarinic acetylcholine receptor (mAChR) subtype. Toxin B treatment of HEK cells did not affect basal PLC activi…

Phosphatidylinositol 45-DiphosphateBotulinum ToxinsG proteinBacterial ToxinsClostridium difficile toxin AClostridium difficile toxin BBiologychemistry.chemical_compoundBacterial ProteinsGTP-Binding ProteinsHeterotrimeric G proteinHumansPhosphatidylinositolCells CulturedADP Ribose TransferasesPharmacologyPhospholipase CHEK 293 cellsGeneral MedicineReceptors MuscarinicMolecular biologyCell biologychemistryPhosphatidylinositol 45-bisphosphateType C PhospholipasesrhoA GTP-Binding ProteinNaunyn-Schmiedeberg's Archives of Pharmacology
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Glucosylation of Rho proteins by Clostridium difficile toxin B.

1995

TOXIN A and B, the major virulence factors of Clostridium difficile, are the causative agents of antibiotic-associated pseudomembran-ous colitis. In cultured cell lines their potent cytotoxicity results from their ability to induce disaggregation of the microfilament cytoskeleton1,2. Toxin B acts on the low-molecular-mass GTPase Rho A3,4, which is involved in the regulation of the actin cytoskeleton. We report here that toxin B catalyses the incorporation of up to one mole of glucose per mole of RhoA at the amino acid thre-onine at position 37. The modification was identified and localized by tandem electrospray mass spectrometry. UDP-glucose selectively serves as cosubstrate for the monogl…

ThreonineRHOAGlycosylationBacterial ToxinsMolecular Sequence DataClostridium difficile toxin AClostridium difficile toxin Bmacromolecular substancesmedicine.disease_causeMicrofilamentCatalysisMass SpectrometryGTP PhosphohydrolasesBacterial ProteinsGTP-Binding ProteinsmedicineTumor Cells CulturedAnimalsAmino Acid SequenceCytoskeletonActinCells CulturedCytoskeletonMultidisciplinarybiologyToxinClostridioides difficileActin cytoskeletonActinsRecombinant ProteinsRatsGlucoseMarsupialiaBiochemistryGlucosyltransferasesbiology.proteinrhoA GTP-Binding ProteinNature
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Clostridium difficile toxin A induces expression of the stress-induced early gene product RhoB.

2004

Clostridium difficile toxin A monoglucosylates the Rho family GTPases Rho, Rac, and Cdc42. Glucosylation leads to the functional inactivation of Rho GTPases and causes disruption of the actin cytoskeleton. A cDNA microarray revealed the immediate early gene rhoB as the gene that was predominantly up-regulated in colonic CaCo-2 cells after treatment with toxin A. This toxin A effect was also detectable in epithelial cells such as HT29 and Madin-Darby canine kidney cells, as well as NIH 3T3 fibroblasts. The expression of RhoB was time-dependent and correlated with the morphological changes of cells. The up-regulation of RhoB was approximately 15-fold and was based on the de novo synthesis of …

RHOAPyridinesRHOBBacterial ToxinsClostridium difficile toxin ARAC1GTPaseBiochemistryp38 Mitogen-Activated Protein KinasesGene Expression Regulation EnzymologicGene productEnterotoxinsStress PhysiologicalRhoB GTP-Binding ProteinHumansrhoB GTP-Binding ProteinMolecular BiologyOligonucleotide Array Sequence AnalysisbiologyImidazolesCell BiologyRhoBClostridium difficileActin cytoskeletonMolecular biologyUp-Regulationbiology.proteinGene expressionCaco-2 CellsThe Journal of biological chemistry
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Rho GTPases are over-expressed in human tumors.

1999

Small GTPases of the Rho family are involved in the regulation of a variety of cellular processes, such as the organization of the microfilamental network, cell-cell contact and malignant transformation. To address the question of whether Rho proteins are involved in carcinogenesis in man, we compared their expression in tumors from colon, breast and lung with that of the corresponding normal tissue originating from the same patient. As shown by Rho-specific 32P-ADP-ribosylation, as well as Western-blot analysis, the amount of RhoA protein was largely increased in all 3 types of tumors tested. The most dramatic differences in the expression of Rho GTPases were observed in breast tissue. All…

rho GTP-Binding ProteinsCancer ResearchPathologymedicine.medical_specialtyRHOALung NeoplasmsColonBreast NeoplasmsCell Cycle ProteinsGTPaseCDC42medicine.disease_causeMalignant transformationGTP PhosphohydrolasesGTP-Binding ProteinsmedicineHumansrho-Specific Guanine Nucleotide Dissociation InhibitorsBreastcdc42 GTP-Binding ProteinrhoB GTP-Binding ProteinLungGuanine Nucleotide Dissociation InhibitorsMitogen-Activated Protein Kinase 1Adenosine Diphosphate RibosebiologyCancerMembrane Proteinsmedicine.diseaseImmunohistochemistryrac GTP-Binding ProteinsOncologyrhoC GTP-Binding ProteinCalcium-Calmodulin-Dependent Protein KinasesColonic Neoplasmsbiology.proteinCancer researchImmunohistochemistryCarcinogenesisrhoA GTP-Binding ProteinRhoC GTP-Binding ProteinInternational journal of cancer
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The Enterotoxin from Clostridium difficile (ToxA) Monoglucosylates the Rho Proteins

1995

The enterotoxin from Clostridium difficile (ToxA) is one of the causative agents of the antibiotic-associated pseudomembranous colitis. In cultured monolayer cells ToxA exhibits cytotoxic activity to induce disassembly of the actin cytoskeleton, which is accompanied by morphological changes. ToxA-induced depolymerization of actin filaments is correlated with a decrease in the ADP-ribosylation of the low molecular mass GTP-binding Rho proteins (Just, I., Selzer, J., von Eichel-Streiber, C., and Aktories, K. (1995) J. Clin. Invest. 95, 1026-1031). Here we report on the identification of the ToxA-induced modification of Rho. Applying electrospray mass spectrometry, the mass of the modification…

RHOAGlycoside HydrolasesBacterial ToxinsClostridium difficile toxin ARAC1macromolecular substancesEnterotoxinBiochemistrySubstrate SpecificityEnterotoxinsGTP-Binding ProteinsTumor Cells CulturedAmino AcidsMolecular BiologyActinbiologyMolecular massClostridioides difficileCell BiologyPseudomembranous colitisActin cytoskeletonMolecular biologycarbohydrates (lipids)GlucoseBiochemistrybiology.proteinrhoA GTP-Binding ProteinJournal of Biological Chemistry
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