When a ligand binds to a G protein-coupled receptor, which of the following would you expect to happen FIRST?
A)The amount of cAMP in the cytoplasm increases.
B)Protein kinase activity increases.
C)Adenylyl cyclase activity increases.
D)Phosphodiesterase activity increases.
E)None of the other answer options is correct.

Question

Quizplus · Accepted Answer

When a ligand binds to a G protein-coupled receptor (GPCR), it activates the G protein associated with the receptor. This activation leads to the stimulation of adenylyl cyclase, an enzyme that catalyzes the conversion of ATP to cyclic AMP (cAMP), thus increasing adenylyl cyclase activity first before any changes in cAMP levels or subsequent signaling events.

When a Ligand Binds to a G Protein-Coupled Receptor, Which