A bacterium releases a toxin that binds to and activates a G protein-coupled receptor in the mammalian gut. The result is high levels of cAMP in these cells. This toxin might work by:
A)binding to and activating the G protein-coupled receptor in these cells.
B)binding to and inhibiting the G protein-coupled receptor in these cells.
C)causing the $\alpha$subunit of the G protein to stay associated with the $\beta$ and $\gamma$ subunits.
D)causing the $\alpha$ subunit of the G protein to bind GDP constantly.
E)causing adenylyl cyclase to dissociate from the membrane.

Question

Quizplus · Accepted Answer

The toxin is binding and activating a G protein-coupled receptor in the mammalian gut, leading to high levels of cAMP in these cells. This suggests that the toxin is acting as an agonist to the receptor, causing it to signal through the associated G protein and resulting in downstream activation of adenylyl cyclase and production of cAMP.

A Bacterium Releases a Toxin That Binds to and Activates α\alphaα

A Bacterium Releases a Toxin That Binds to and Activates $\alpha$