0000000000454962

AUTHOR

Michel R. Popoff

showing 2 related works from this author

UDP-glucose deficiency in a mutant cell line protects against glucosyltransferase toxins from Clostridium difficile and Clostridium sordellii.

1996

Abstract We have previously isolated a fibroblast mutant cell with high resistance to the two Rho-modifying glucosyltransferase toxins A and B of Clostridium difficile. We demonstrate here a low level of UDP-glucose in the mutant, which explains its toxin resistance since: (i) to obtain a detectable toxin B-mediated Rho modification in lysates of mutant cells, addition of UDP-glucose was required, and it promoted the Rho modification dose-dependently; (ii) high pressure liquid chromatography analysis of nucleotide extracts of cells indicated that the level of UDP-glucose in the mutant (0.8 nmol/106 cells) was lower than in the wild type (3.7 nmol/106 cells); and (iii) sensitivity to toxin B…

Uridine Diphosphate GlucoseMicroinjectionsMutantBacterial ToxinsClostridium difficile toxin AClostridium sordelliiClostridium difficile toxin Bmedicine.disease_causeBiochemistryMicrobiologyCell LineCricetulusBacterial ProteinsGTP-Binding ProteinsCricetinaemedicineAnimalsMolecular BiologyClostridiumbiologyToxinClostridioides difficileWild typeCell BiologyClostridium difficilebiology.organism_classificationGlucosyltransferasesMutationbiology.proteinGlucosyltransferaseThe Journal of biological chemistry
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Ras, Rap, and Rac Small GTP-binding Proteins Are Targets for Clostridium sordellii Lethal Toxin Glucosylation

1996

Lethal toxin (LT) from Clostridium sordellii is one of the high molecular mass clostridial cytotoxins. On cultured cells, it causes a rounding of cell bodies and a disruption of actin stress fibers. We demonstrate that LT is a glucosyltransferase that uses UDP-Glc as a cofactor to covalently modify 21-kDa proteins both in vitro and in vivo. LT glucosylates Ras, Rap, and Rac. In Ras, threonine at position 35 was identified as the target amino acid glucosylated by LT. Other related members of the Ras GTPase superfamily, including RhoA, Cdc42, and Rab6, were not modified by LT. Incubation of serum-starved Swiss 3T3 cells with LT prevents the epidermal growth factor-induced phosphorylation of m…

ThreonineUridine Diphosphate GlucoseRHOABacterial ToxinsMolecular Sequence DataClostridium sordelliimacromolecular substancesCDC42GTPaseBiologyCell morphologyBiochemistryGTP PhosphohydrolasesProto-Oncogene Proteins p21(ras)MiceGTP-binding protein regulatorsGTP-Binding ProteinsAnimalsHumansAmino Acid SequenceMolecular BiologyClostridiumEpidermal Growth FactorKinase3T3 CellsCell Biologybiology.organism_classificationMolecular biologyActinsrac GTP-Binding ProteinsActin CytoskeletonKineticsGlucoserap GTP-Binding ProteinsGlucosyltransferasesCalcium-Calmodulin-Dependent Protein Kinasesbiology.proteinPhosphorylationGuanosine TriphosphateHeLa CellsJournal of Biological Chemistry
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