Deactivation
The Gs alpha subunit slowly catalyzes the hydrolysis of GTP to GDP, which in turn deactivates the Gs protein, shutting off the cAMP pathway. The pathway may also be deactivated downstream by directly inhibiting adenylyl cyclase or dephosphorylating the proteins phosphorylated by PKA.
Molecules that inhibit the cAMP pathway include:
- cAMP phosphodiesterase dephospohorylates cAMP into AMP, reducing the cAMP levels
- Gi protein, which is a G protein that inhibits adenylyl cyclase, reducing cAMP levels.
Read more about this topic: CAMP-dependent Pathway