G protein-coupled receptors sense stimuli outside the cell and transmit signals across the plasma membrane. Activation of protein kinase C (PKC) is one of the common signaling pathways. When a class of GPCRs are activated by a ligand, they activate Gq protein to bind GTP instead of GDP. After the Gq becomes active, it activates phospholipase C (PLC) to cleave the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) into inositol 1,4,5-trisphosphate (IP3) and diacyl glycerol (DAG). IP3 can bind Ins3P receptor to open calcium channel by diffusion from cytoplasm to ER. Activated calcium channel will release the calcium from ER into cytoplasm. Calcium can activate the kinase activity of PKC.

Activation of PKC Through G Protein-Coupled Receptor References