De-ADP-ribosylation actin by Clostridium perfringens iota-toxin and Clostridium botulinum C2 toxin.
The reverse reaction of the ADP-ribosylation of actin by Clostridium botulinum C2 toxin and Clostridium perfringens iota-toxin was studied. In the presence of nicotinamide (30-50 mM) C2 toxin and iota-toxin decreased the radioactive labeling of [32P]ADP-ribosylated actin and catalyzed the formation of [32P]NAD. The pH optima for both reactions were 5.5-6.0. Concomitant with the removal of ADP-ribose, the ability of actin to polymerize was restored and actin ATPase activity increased. Neither ADP-ribosylation nor removal of ADP-ribose was observed after treatment of actin with EDTA, indicating that the native structure of actin is required for both reactions. ADP-ribosylation of platelet actin by C2 toxin was reversed by iota-toxin, confirming recent reports that both toxins modify the same amino acid in actin. However, C. botulinum C2 toxin was not able to cleave ADP-ribose from skeletal muscle actin which had been incorporated by iota-toxin, corroborating the different substrate specificities of both toxins.
Just
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I
Pharmakologisches Institut, Universitätsklinikums Essen, Federal Republic of Germany.
Geipel
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U
Wegner
A
A
Aktories
K
K
D036002:ADP Ribose Transferases; D000199:Actins / Q000737:chemistry / Q000378:metabolism*; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology*; D001905:Botulinum Toxins / Q000494:pharmacology*; D002478:Cells, Cultured / Q000187:drug effects; D004492:Edetic Acid / Q000494:pharmacology; D009132:Muscles / Q000187:drug effects / Q000378:metabolism; D009243:NAD / Q000494:pharmacology; D011817:Rabbits
D000199:Actins; D001427:Bacterial Toxins; C050737:iota toxin, Clostridium perfringens; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D004492:Edetic Acid; D036002:ADP Ribose Transferases; D001905:Botulinum Toxins; D000251:Adenosine Triphosphatases