7e6u
the complex of inactive CaSR and NB2D11
Structural highlights
DiseaseCASR_HUMAN Autosomal dominant hypocalcemia;Familial isolated hypoparathyroidism due to impaired PTH secretion;Neonatal severe primary hyperparathyroidism;Familial hypocalciuric hypercalcemia type 1;Bartter syndrome with hypocalcemia. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. Disease susceptibility is associated with variations affecting the gene represented in this entry. Homozygous defects in CASR can be a cause of primary hyperparathyroidism in adulthood. Patients suffer from osteoporosis and renal calculi, have marked hypercalcemia and increased serum PTH concentrations. FunctionCASR_HUMAN Senses changes in the extracellular concentration of calcium ions. The activity of this receptor is mediated by a G-protein that activates a phosphatidylinositol-calcium second messenger system. Publication Abstract from PubMedHuman calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that maintains Ca(2+) homeostasis in serum. Here, we present the cryo-electron microscopy structures of the CaSR in the inactive and agonist+PAM bound states. Complemented with previously reported structures of CaSR, we show that in addition to the full inactive and active states, there are multiple intermediate states during the activation of CaSR. We used a negative allosteric nanobody to stabilize the CaSR in the fully inactive state and found a new binding site for Ca(2+) ion that acts as a composite agonist with L-amino acid to stabilize the closure of active Venus flytraps. Our data show that agonist binding leads to compaction of the dimer, proximity of the cysteine-rich domains, large-scale transitions of 7-transmembrane domains, and inter- and intrasubunit conformational changes of 7-transmembrane domains to accommodate downstream transducers. Our results reveal the structural basis for activation mechanisms of CaSR and clarify the mode of action of Ca(2+) ions and L-amino acid leading to the activation of the receptor. Structural insights into the activation of human calcium-sensing receptor.,Chen X, Wang L, Cui Q, Ding Z, Han L, Kou Y, Zhang W, Wang H, Jia X, Dai M, Shi Z, Li Y, Li X, Geng Y Elife. 2021 Sep 1;10. pii: 68578. doi: 10.7554/eLife.68578. PMID:34467854[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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