Gq proteins

Gq Proteins are class of G proteins. Gq proteins works to activate phospholipase C (PLC) in which allows it to be involved in many physiological activities, including taste, manic depression, tumor promotion, etc. 1

The Gq protein works by activating PLC. PLC then cleaves a phospholipid. In the process, phosphatidylinositol 4,5-bisphosphate (PIP2) is cleaved into diacylglyercol (DAG) and inositol 1,4,5-triphosphate (IP3). DAG remains on bound to the membrane, and IP3 is released as a soluble structure into the cytosol. IP3 then diffuses through the cytosol to bind particular Calcium ion channels in the endoplasmic reticulum (ER). These channels are IP3 gated, and open when IP3 is bound to it. These channels are specific to Calcium and only allow the passage of Calcium to move through. This causes the cytosolic concentration of Calcium to increase, causing a cascade of intracellular changes and activity. 1

In addition, Calcium and DAG together works to activate protein kinase C (PKC) in which goes on to phosphorylate other things, leading to altered cellular activity. 1

1 Alberts, et al. "Molecular Biology: The Cell. 4th edition."