When ligand binds the GPCR, the G protein
- A
Translates the bound mRNA into a new effector protein at ribosomes near the membrane surface
- Bcheck_circle
Exchanges GDP for GTP and the activated α-subunit then activates downstream effectors (e.g., adenylyl cyclase)
- C
Dissociates entirely from the receptor and shuttles the ligand into the cytoplasm for processing
- D
Hydrolyzes ATP to ADP and uses the released energy to phosphorylate downstream kinases directly
Explanation
The ligand-bound receptor catalyzes GDP → GTP exchange on Gα, activating it. Gα regulates downstream enzymes; eventually GTP is hydrolyzed to GDP, ending signaling.