What is inositol triphosphate?

Inositol triphosphate, a small signal molecule, is used as an assistant messenger in the signal pathway It consists of a central six carbon ring with three hydroxyl (OH) and three phosphate (PO4) 2 groups Carbonates are attached to the first, fourth and fifth carbon atoms, giving this molecule a more specific name of nositol 1,4,5-trisphosphonate When the cell membrane is produced, it is a polar molecule with - 6 charge Therefore, it has the ability to leave the cell membrane and pass through the cytoplasm This activity is required for molecular binding to its receptor, whose receptor is to separate the calcium channel of glycoprotein in the organelle membrane (endoplasmic reticulum or sarcoplasmic reticulum) Inositol triphosphate plays an important role in the pathway opened by α 1 - (A1) adrenergic receptor, which leads to contraction of smooth muscle to adrenaline This pathway constricts blood vessels in the skin, digestive system, and parts of the brain during the body's defense response It occurs in the central and peripheral nervous systems The pathway involved in inositol triphosphate begins with the release of ligands or hormones into the bloodstream Hormone initiates signal pathway by binding to GPCR G-protein coupled receptor (GPCR) is a kind of protein embedded in cell membrane and connected with G-protein When Binding hormones, the receptor takes place conformational changes, activating G protein and binding guanosine triphosphate (GTP) as energy The activated G protein binds through the cell membrane and activates phospholipase C The enzyme breaks down phosphoinositide 4,5-diphosphate, a membrane phospholipid molecule, into two smaller molecules: diacylglycerol and inositol triphosphate Diacylglycerol remains in the membrane, while inositol triphosphate passes through the cytoplasm of cells, binding calcium channels on one of the organelle membranes Depending on the cell type, inositol triphosphate binds to channels on the surface of the endoplasmic reticulum or sarcoplasmic reticulum In both cases, inositol triphosphate opens the channel and releases Ca2 + ions into the cell These ions bind to and activate another enzyme called protein kinase C, which phosphates other proteins and produces a total cell response to hormone messengers.