text: The G alpha subunit slowly catalyzes the hydrolysis of GTP to GDP, which in turn deactivates the G 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 converts cAMP into AMP by breaking the phosphodiester bond, in turn reducing the cAMP levels
  * G protein, which is a G protein that inhibits adenylyl cyclase, reducing cAMP levels.