ADP-ribosylation byClostridium botulinumC3 exoenzyme increases steady-state GTPase activities of recombinant rhoA and rhoB proteins

Exoenzyme S shows selective ADP-ribosylation and GTPase-activating protein (GAP) activities towards small GTPases in vivo.

Intracellular targeting of the Pseudomonas aeruginosa toxins exoenzyme S (ExoS) and exoenzyme T (ExoT) initially results in disruption of the actin microfilament structure of eukaryotic cells. ExoS and ExoT are bifunctional cytotoxins, with N-terminal GTPase-activating protein (GAP) and C-terminal ADP-ribosyltransferase activities. We show that ExoS can modify multiple GTPases of the Ras superf...

Poliovirus proteins induce membrane association of GTPase ADP-ribosylation factor.

Poliovirus infection results in the disintegration of intracellular membrane structures and formation of specific vesicles that serve as sites for replication of viral RNA. The mechanism of membrane rearrangement has not been clearly defined. Replication of poliovirus is sensitive to brefeldin A (BFA), a fungal metabolite known to prevent normal function of the ADP-ribosylation factor (ARF) fam...

ADP-ribosylation of p21ras and related proteins by Pseudomonas aeruginosa exoenzyme S.

Pseudomonas aeruginosa exoenzyme S ADP-ribosylates p21ras and several related proteins. ADP-ribosylation of p21ras does not alter interactions with guanine nucleotides. The ras-related GTP-binding proteins, including Rab3, Rab4, Ral, Rap1A, and Rap2, are also substrates; given these results, we propose a model for the role of exoenzyme S in pathogenesis.

ADP-ribosylation of nuclear proteins.

ADP-ribosylation can be defined as the postsynthetic modification of protein by the covalent attachment of the ADP-ribose moiety of NAD+. ADP-ribosylation of elongation-factor Tu is responsible for the inhibition of protein synthesis by both diptheria and Pseudomonas aeroginosa toxins (Hilz & Stone, 1976). The activation of membrane adenylate cyclase by cholera toxin is thought to occur by ADP-...

ADP-Ribosylation of T Cell Surface Proteins