Gi alpha subunit (Gαi, or Gi/G0 or Gi protein) is a heterotrimeric G protein subunit that inhibits the production of cAMP from ATP. A mnemonic for remembering this subunit is to look at first letter (Gαi = Adenylate Cyclase inhibitor).
It is also attributed a minor role in activation of the phospholipase C pathway. Growth hormone is required for normal postnatal growth, bone growth, regulatory effects on protein, carbohydrate, and lipid metabolism. although this is mainly a function of the Gq alpha subunit.