What is the result of exposure to cholera toxin in humans? Be brief How does cholera toxin work? What does it do to susceptible cells? Be more detailed Solution Answer : Question number 1 :Cholera toxin acts on a G protein that is part of a signaling pathway (see Fig. 12–39), leading to several physiological responses including a massive loss of body fluids and, sometimes, death.The ultimate problem with cholera that can lead to death is severe dehydration and electrolyte imbalance. Question number 2 : Cholera toxin produced by Vibrio cholerae catalyzes the ribosylation by tranfering ADP-ribose from NAD+ to the alpha subunit of Gs (Stimulatory G protein) and prevents its GTPase activity making it permanently activated. This results in continuous activation of the adenylyl cyclase of intestinal epithelial cells and high cAMP levels, resulting in constant secretion of Cl-, HCO3- , and water into the intestinal lumen. The resulting dehydration and electrolyte loss are the major pathologies in cholera..

1. What is the result of exposure to cholera toxin in humans? Be brief How does cholera toxin
work? What does it do to susceptible cells? Be more detailed
Solution
Answer :
Question number 1 :Cholera toxin acts on a G protein that is part of a signaling pathway (see Fig.
12–39), leading
to several physiological responses including a massive loss of body fluids and, sometimes,
death.The ultimate problem with cholera that can lead to death is severe dehydration and
electrolyte imbalance.
Question number 2 : Cholera toxin produced by Vibrio cholerae catalyzes the ribosylation by
tranfering ADP-ribose from NAD+ to the alpha subunit of Gs (Stimulatory G protein) and
prevents its GTPase activity making it permanently activated. This results in continuous
activation of the adenylyl cyclase of intestinal epithelial cells and high cAMP levels, resulting in
constant secretion of Cl-, HCO3- , and water into the intestinal lumen. The resulting dehydration
and electrolyte loss are the major pathologies in cholera.