Extracellular calcium-sensing receptor (CASR) is a ~120 kDa protein. G-protein-coupled receptor that senses changes in the extracellular concentration of calcium ions and plays a key role in maintaining calcium homeostasis. Senses fluctuations in the circulating calcium concentration: activated by elevated circulating calcium, leading to decreased parathyroid hormone (PTH) secretion in parathyroid glands. In kidneys, acts as a key regulator of renal tubular calcium resorption. Ligand binding causes a conformation change that triggers signaling via guanine nucleotide-binding proteins (G-proteins) and modulates the activity of downstream effectors. CASR is coupled with different G(q)/G(11), G(i)/G(o)- or G(s)-classes of G-proteins depending on the context. 1. Tõke, J. et al. (2007) Clinical endocrinology 67, 385-92. PMID: 175555082. Lietman, SA. et al. (2009) The Journal of clinical endocrinology and metabolism 94, 4372-9. PMID: 197892093. Al-Salameh, A. et al. (2011) European journal of endocrinology 165, 359-63. PMID: 215660755. Guarnieri, V. et al. (2012) Molecular genetics and metabolism 107, 548-52. PMID: 227896836. Nakamura, A. et al. (2013) The Journal of clinical endocrinology and metabolism 98, E1692-701. PMID: 239662417. Stratta, P. et al. (2014) Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association 29, 1902-9. PMID: 251040828. Mastromatteo, E. et al. (2014) BMC endocrine disorders 14, 81. PMID: 252921849. Baran, N. et al. (2015) Molecular and cellular endocrinology 407, 18-25. PMID: 2576650110. Kim, ES. et al. (2016) Journal of bone and mineral metabolism 34, 662-667. PMID: 26386835 | 
