ADP‐ribosylation by Clostridium botulinum C3 exoenzyme increases steady‐state GTPase activities of recombinant rhoA and rhoB proteins

FEBS Letters

Mohr, Christiane¹  Just, Ingo²  Aktories, Klaus¹  Koch, Gertrud² 

[1]Rudolf-Buchheim-Institut für Pharmakologie der Universität Gießen, D-6300 Gießen, Germany

[2]Institut für Pharmakologie und Toxikologie der Universität des Saarlandes, D-6650 Homburg/Saar, Germany

关键词: ADP-ribosylation;    Cloytridium botulinum C3 exoenzyme;    GTPase;    rho Protein;    GTP-binding;   

DOI  :  10.1016/0014-5793(92)80335-E

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

ADP-ribosylation of recombinant rhoA and rhoB proteins by Clostridium botulinum C3 exoenzyme increased steady-state GTP hydrolysis by 50 to 80%. ADP-ribosylation and increase in GTP hydrolysis occurred at similar concentrations of C3, depended on the presence of NAD and were prevented by anti-C3 antibody or heat inactivation of C3. In contrast, GTP hydrolysis by Ile-41 rhoA or Ha-ras, which are no substrates for the transferase, were not affected by C3. ADP-ribosylation facilitated the [³H]GDP release and subsequently, the binding of [³H]GTP to rhoA. The data indicate that the increase in the steady-state GTPase activity by ADP-ribosylation is caused by increasing the rate of GDP release which is suggested to be the rate limiting step of the GTPase cycle of the small GTP-binding proteins.

【 授权许可】

Unknown