ADP-ribosylation of actin by Clostridium perfringens iota toxin and turkey erythrocyte ADP-ribosyltransferase A: Effects on profilin-regulated nucleotide exchange and ATPase activity
Sehr, P.; Just, I.; Aktories, K.
Naunyn-Schmiedeberg's Archives of Pharmacology 354(6): 693-697
Effects of ADP-ribosylation of skeletal muscle alpha-actin by Clostridium perfringens iota toxin and by turkey erythrocyte ADP-ribosyltransferase A on profilin-regulated nucleotide exchange and ATPase activity were compared. ADP-ribosylation of actin at Arg177 by Clostridium perfringens iota toxin increased the nucleotide dissociation rate from 2.2 times 10-3 s-1 to 4.5 times 10-3 s-1 without affecting the profilin-induced stimulation of nucleotide exchange. In contrast, ADP-ribosylation of actin at Arg95/Arg372 induced by turkey erythrocyte transferase decreased the nucleotide dissociation rate to 1.5 times 10-3 s-1 and inhibited the profilin-induced stimulation of nucleotide exchange. Whereas toxin-induced ADP-ribosylation at Arg177 blocked actin ATPase, basal G-actin ATPase was not altered by ADP-ribosylation at Arg95/Arg372 but inhibited profilin effects on actin ATPase.