The N-terminal domain of Pseudomonas aeruginosa exoenzyme S is a GTPase-activating protein for Rho GTPases.
J Biol Chem
; 274(51): 36369-72, 1999 Dec 17.
Article
en En
| MEDLINE
| ID: mdl-10593930
ABSTRACT
Pseudomonas aeruginosa exoenzyme S (ExoS) is a bifunctional cytotoxin. The ADP-ribosyltransferase domain is located within the C terminus part of ExoS. Recent studies showed that the N terminus part of ExoS (amino acid residues 1-234, ExoS(1-234)), which does not possess ADP-ribosyltransferase activity, stimulates cell rounding when transfected or microinjected into eukaryotic cells. Here we studied the effects of ExoS(1-234) on nucleotide binding and hydrolysis by Rho GTPases. ExoS(1-234) (100-500 nM) did not influence nucleotide exchange of Rho, Rac, and Cdc42 but increased GTP hydrolysis. A similar increase in GTPase activity was stimulated by full-length ExoS. Half-maximal stimulation of GTP hydrolysis by Rho, Rac, and Cdc42 was observed at 10-11 nM ExoS(1-234), respectively. We identified arginine 146 of ExoS to be essential for the stimulation of GTPase activity of Rho proteins. These data identify ExoS as a GTPase-activating protein for Rho GTPases.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Pseudomonas aeruginosa
/
Toxinas Bacterianas
/
ADP Ribosa Transferasas
/
Proteínas de Unión al GTP rho
/
Proteínas Activadoras de GTPasa
Idioma:
En
Revista:
J Biol Chem
Año:
1999
Tipo del documento:
Article
País de afiliación:
Alemania