Bacterial protein toxins inhibiting low-molecular-mass GTP-binding proteins.
The Rho GTPases, which belong to the Ras superfamily of low-molecular-mass GTP-binding proteins, are the preferred intracellular targets of bacterial protein toxins. The Rho GTPases RhoA/B/C, Rac1/2 and Cdc42 are the master regulators of the actin cytoskeleton. Clostridium difficile toxins A and B, the causative agents of the antibiotic-associated pseudomembranous colitis, are intracellularly acting cytotoxins which mono-glucosylate the Rho GTPases. Clostridium botulinum C3 toxin, which is not related to the clostridial neurotoxins, catalyses ADP-ribosylation of RhoA/B/C but not of other Rho GTPases. Glucosylation as well as ADP-ribosylation result in functional inactivation of Rho causing disassembly of the actin cytoskeleton.
Just
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Institut für Toxikologie, Medizinische Hochschule Hannover, Germany. just.ingo@mh-hannover.de
Hofmann
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Genth
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Gerhard
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D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001906:Botulism / Q000382:microbiology / Q000503:physiopathology; D002478:Cells, Cultured; D016360:Clostridioides difficile / Q000378:metabolism / Q000472:pathogenicity; D003014:Clostridium botulinum / Q000378:metabolism / Q000472:pathogenicity; D004761:Enterocolitis, Pseudomembranous / Q000382:microbiology / Q000503:physiopathology; D006801:Humans; D020741:rho GTP-Binding Proteins / Q000037:antagonists & inhibitors*
D001427:Bacterial Toxins; D020741:rho GTP-Binding Proteins