7E6T

Structural insights into the activation of human calcium-sensing receptor

Summary for 7E6T

• Entry DOI: 10.2210/pdb7e6t/pdb
• EMDB information: 30996
• Descriptor: Extracellular calcium-sensing receptor, PHOSPHATE ION, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: g-protein-coupled receptor (gpcr); calcium-sensing receptor (casr); cryo-electron microscopy (cryo-em); calcium ions; nanobody, structural protein
• Biological source: Homo sapiens (Human)
• Total number of polymer chains: 2
• Total formula weight: 196399.90

Authors

Geng, Y.,Chen, X.C.,Wang, L.,Cui, Q.Q.,Ding, Z.Y.,Han, L.,Kou, Y.J.,Zhang, W.Q.,Wang, H.N.,Jia, X.M.,Dai, M.,Shi, Z.Z.,Li, Y.Y.,Li, X.Y. (deposition date: 2021-02-24, release date: 2021-09-22, Last modification date: 2024-11-20)

Primary citation

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.
Structural insights into the activation of human calcium-sensing receptor.
Elife, 10:-, 2021

PubMed Abstract: Human calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that maintains Ca 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 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 seven-transmembrane domains, and inter- and intrasubunit conformational changes of seven-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 ions and L-amino acid leading to the activation of the receptor.

PubMed: 34467854
DOI: 10.7554/eLife.68578

Experimental method

ELECTRON MICROSCOPY (3 Å)