Question: Whereas the cholera toxin ADP-ribosylates the α subunit of
stimulatory G protein (Gs), thereby bl…
Whereas the cholera toxin ADP-ribosylates the α subunit of
stimulatory G protein (Gs), thereby blocking GTP hydrolysis,
pertussis toxin ADP-ribosylates the α subunit of inhibitory G
protein (Gi) 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