Microbiology – MCQ 41 – Mechanism of action of cholera toxin

In the small intestine, cholera toxin acts by:
A. ADP-ribosylation of the G regulatory protein
B. Inhibition of adenyl cyclase
C. Activation of GTPase
D. Active absorption of NaCl

Correct answer : A. ADP-ribosylation of the G regulatory protein

Cholera toxin increases adenyl cyclase activity by irreversible ADP ribosylation of GTP binding domain of adenyl cyclase.