In: Biology
Explain how the activity of adenylyl cyclase can be regulation G-proteins ? (short explain)
Adenylyl cyclase activity is controlled by heterotrimetric G protein. one especially common target of activated G proteins is adenylyl cyclase, a membrane associated enzyme that when activated by GTP bound alpha subunit, catalyzes synthesis of second messenger cyclic AMP from molecules of ATP.
the inactive or inhibitory forms exists when complex consists of alpha,beta and gamma subunit, with GDP bound to alpha subunit.in order to become active, a ligans must bind to receptor and cause a conformational change.the conformational change causes the alpha subunit to dissociate from the complex and become bound to GTP.this G-alpha GTP complex then binds to adenylyl cyclase and causes activation and the release of cAMP.
the deactivation of active G-alpha-GTP complex is accomplished rapidly by GTP hydrolysis due to the reaction catalyzed by intrinsic enzymatic activity of GTPase located in alpha subunit.it is also regulated by forskolin, as well as other isoform specific effectors.