Phospholipase physiological’ effects

Agonist occupancy of GPCRs, such as the delta opioid receptor, leads to physiological effects through interactions with heterotrimeric G proteins. Such G proteins consist of a Ga subunit and its Gpy dimeric partner. There are four major families of Ga proteins with different profiles of effector interaction 1) Gas, which activate adenylyl cyclase 2) Gai/o, so-called inhibitory G proteins named for their ability to inhibit adenylyl cyclase, but interact with many effectors 3) Gaq/11, which activate phospholipase C- 3 (PLC- 3) and 4) Gal2/13, which may regulate small GTP-binding proteins. Delta opioid receptors, like mu and kappa opioid receptors, couple to mem-... 

Turkey erythrocytes also possess a purinergic receptor, which is linked through a G-protein to a phosphoinositide phospholipase C (Ruiz-Larrea Berrie, 1993). Purinergic receptors are activated by extracellular ATP, ADP and AMP, which occur in low concentration outside cells and have physiological effects. They are known to be released by exocy tosis from adrenal chromaffin granules. 

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