Inositol phospholipid signalling pathway
The Inositol signalling pathway is activated when a signal molecule binds to the receptor of a trimeric G protein. The binding of the signal molecule causes the GDP bound to the G protein to exchanged for GTP, this induces a conformational change and the alpha subunit dissociates itself from the beta and gamma subunits. The alpha subunit then activates phospholipase C. The phospholipase C then cleaves phosphoinositol 4,5- biphosphate (PIP2); producing Diacylglycerol (DAG) and Inositol 1,4,5 triphosphate (IP3). DAG remains embedded in the phospholipid membrane, whereas IP3 moves into the cytoplasm. IP3 then binds to IP3 gated Ca2+ release channels on the membrane of the endoplasmic reticulum, this in turn releases Ca2+ ions, which binds to Protein Kinase C (PKC). The DAG also binds to PKC, which consequently activates the Protein Kinase C. The PKC then phosphorylates various proteins in order to amplify the signal.
- ↑ Alberts B, Johnson A, Lewis J, Morgan D, Raff M, Roberts K, Walter P. Molecular Biology of THE CELL. 6th edition. New York: Garland Science, Taylor & Francis Group, LLC, an informa bussiness. 2015