calcium signaling pathway via the calcium-sensing receptor +
Calcium signaling through the calcium-sensing receptor inhibits the secretion of parathyroid hormone in the parathyroid glands and controls calcium absorption and water balance in the kidneys. Calcium is considered the main physiological agonist but other cations and various agonists can activate the receptor. The G protein coupled receptor (GPCR) is believed to engage several types of Galpha proteins and to have many other interacting partners. The pathway leads to activation of MAPK cascades, particularly the one mediated by Erk1/2. Casr signaling is cell specific; many of its molecular details are not fully understood. Many mutations, both inactivating and activating the receptor, have been identified.