title: Cellular ADP-ribosyltransferase with the same mechanism of action as diphtheria toxin and Pseudomonas toxin A.
abstract: An ADP-ribosyltransferase was found in elongation factor 2 (EF-2) preparations from polyoma virus-transformed baby hamster kidney (pyBHK) cells. Like fragment A of diphtheria toxin and Pseudomonas toxin A, this eukaryotic cellular enzyme transfers [14C]adenosine from NAD+ to EF-2. However, the cellular transferase is immunologically distinct from fragment A. The transferase also can be distinguished from fragment A and Pseudomonas toxin A by the inhibition of the activity of the former by cytoplasmic extracts and by histamine. Snake venom phosphodiesterase digestion of the [14C]adenosine-labeled EF-2 product of the cellular transferase reaction yielded [14C]AMP, indicating that the cellular enzyme is a mono(ADP-ribosyl)transferase. The forward ADP-ribosylation reaction catalyzed by the cellular enzyme is reversed by fragment A, yielding [14C]NAD+. The results strongly suggest that the cellular transferase is a mono(ADP-ribosyl)transferase, which ADP-ribosylates the same diphthamide residue of EF-2 as does fragment A and Pseudomonas toxin A.
mesh_terms: D036002:ADP Ribose Transferases; D000818:Animals; D001427:Bacterial Toxins; D006224:Cricetinae; D004167:Diphtheria Toxin / Q000378:metabolism*; D005098:Exotoxins / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009713:Nucleotidyltransferases / Q000378:metabolism*; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000378:metabolism*; D011065:Poly(ADP-ribose) Polymerases; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D001427:Bacterial Toxins; D004167:Diphtheria Toxin; D005098:Exotoxins; D009243:NAD; D009713:Nucleotidyltransferases; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D011065:Poly(ADP-ribose) Polymerases; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A