Question: Cell and Developmental Biology Question, Multiple Choice Whereas the cholera toxin ADP-ribosylate…

Cell and Developmental Biology Question, Multiple Choice

Whereas the cholera toxin ADP-ribosylates the α subunit of
stimulatory G protein (G_s), thereby blocking GTP
hydrolysis, pertussis toxin ADP-ribosylates the α subunit of
inhibitory G protein (G_i) and prevents interaction with
the receptor. What is the effect of these toxins on the
concentration of intracellular cAMP?

A. Cholera toxin tends to increase cAMP concentration, whereas
pertussis toxin tends to decrease cAMP concentration.

B. Cholera toxin tends to decrease cAMP concentration, whereas
pertussis toxin tends to increase cAMP concentration.

C. They both tend to increase cAMP concentration

D. They both tend to decrease cAMP concentration.