title: ADP-ribosylation in cultured cells treated with Clostridium difficile toxin B.
abstract: In cultured fibroblasts intoxicated with Clostridium difficile toxin B, a radioactive moiety was transferred from [14C-adenosine]NAD, but not from [14C-nicotinamide] NAD, into a cellular protein (MW 90,000). No labeling was detected in toxin-treated cultures not yet showing any toxin-induced cytopathogenic effect, whereas maximal labeling was obtained in cultures with about half of the cells showing a cytopathogenic effect. The radioactivity was removed from the substrate by treatment with snake venom phosphodiesterase. The results suggest that ADP-ribosylation of a cellular protein occurs in toxin B-treated cells and that this reaction may be responsible for development of the cytopathogenic effect.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000096:biosynthesis*; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000633:toxicity*; D002250:Carbon Radioisotopes; D002478:Cells, Cultured; D006801:Humans; D009243:NAD / Q000378:metabolism; D009536:Niacinamide / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D002250:Carbon Radioisotopes; C031815:toxB protein, Clostridium difficile; D009243:NAD; D000246:Adenosine Diphosphate Ribose; D009536:Niacinamide