Inositol 1,4,5-trisphosphate receptor in the liver: Expression and function

Figure 3 Calcium signaling. After the ligation of an agonist to its receptor, here represent by the ligation of acetylcholine to muscarinic acetylcholine receptor, phospholipase C is activated and produces 1,4,5 inositol triphosphate. The inositol 1,4,5-trisphosphate binds its receptor, inositol 1,4,5-trisphosphate receptor, that is expressed mainly along the endoplasmic reticulum, leading to Ca²⁺ release into the cytosol. Ach: Acetylcholine; M3R: Muscarinic acetylcholine receptor; PLC: Phospholipase C; InsP₃: Inositol 1,4,5-trisphosphate; ITPR: Inositol 1,4,5-trisphosphate receptor; ER: Endoplasmic reticulum.