Inhibition of cytochalasin D-stimulated G-actin ATPase by ADP-ribosylation with Clostridium perfringens iota toxin.
Clostridium perfringens iota toxin belongs to a novel family of actin-ADP-ribosylating toxins. The effects of ADP-ribosylation of skeletal muscle actin by Clostridium perfringens iota toxin on cytochalasin D-stimulated actin ATPase activity was studied. Cytochalasin D stimulated actin-catalysed ATP hydrolysis maximally by about 30-fold. ADP-ribosylation of actin completely inhibited cytochalasin D-stimulated ATP hydrolysis. Inhibition of ATPase activity occurred at actin concentrations below the critical concentration (0.1 microM), at low concentrations of Mg2+ (50 microM) and even in the actin-DNAase I complex, indicating that ADP-ribosylation of actin blocks the ATPase activity of monomeric actin and that the inhibitory effect is not due to inhibition of the polymerization of actin.
Geipel
U
U
Rudolf-Buchheim-Institut für Pharmakologie, Universität Giessen, Federal Republic of Germany.
Just
I
I
Aktories
K
K
D036002:ADP Ribose Transferases; D000199:Actins / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D003016:Clostridium perfringens; D015638:Cytochalasin D / Q000494:pharmacology*; D003850:Deoxyribonuclease I / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007700:Kinetics; D046911:Macromolecular Substances; D011485:Protein Binding; D011817:Rabbits
D000199:Actins; D001427:Bacterial Toxins; D046911:Macromolecular Substances; C050737:iota toxin, Clostridium perfringens; D000246:Adenosine Diphosphate Ribose; D015638:Cytochalasin D; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D036002:ADP Ribose Transferases; D003850:Deoxyribonuclease I; D000251:Adenosine Triphosphatases