8SZI

Cryo-EM structure of PAM-free human calcium-sensing receptor CaSR-Gi complex in lipid nanodiscs


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Allosteric modulation and G-protein selectivity of the Ca 2+ -sensing receptor.

He, F.Wu, C.G.Gao, Y.Rahman, S.N.Zaoralova, M.Papasergi-Scott, M.M.Gu, T.J.Robertson, M.J.Seven, A.B.Li, L.Mathiesen, J.M.Skiniotis, G.

(2024) Nature 626: 1141-1148

  • DOI: https://doi.org/10.1038/s41586-024-07055-2
  • Primary Citation of Related Structures:  
    8SZF, 8SZG, 8SZH, 8SZI

  • PubMed Abstract: 

    The calcium-sensing receptor (CaSR) is a family C G-protein-coupled receptor 1 (GPCR) that has a central role in regulating systemic calcium homeostasis 2,3 . Here we use cryo-electron microscopy and functional assays to investigate the activation of human CaSR embedded in lipid nanodiscs and its coupling to functional G i versus G q proteins in the presence and absence of the calcimimetic drug cinacalcet. High-resolution structures show that both G i and G q drive additional conformational changes in the activated CaSR dimer to stabilize a more extensive asymmetric interface of the seven-transmembrane domain (7TM) that involves key protein-lipid interactions. Selective G i and G q coupling by the receptor is achieved through substantial rearrangements of intracellular loop 2 and the C terminus, which contribute differentially towards the binding of the two G-protein subtypes, resulting in distinct CaSR-G-protein interfaces. The structures also reveal that natural polyamines target multiple sites on CaSR to enhance receptor activation by zipping negatively charged regions between two protomers. Furthermore, we find that the amino acid L-tryptophan, a well-known ligand of CaSR extracellular domains, occupies the 7TM bundle of the G-protein-coupled protomer at the same location as cinacalcet and other allosteric modulators. Together, these results provide a framework for G-protein activation and selectivity by CaSR, as well as its allosteric modulation by endogenous and exogenous ligands.


  • Organizational Affiliation

    Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Guanine nucleotide-binding protein G(i) subunit alpha-3A [auth C]354Homo sapiensMutation(s): 4 
Gene Names: GNAI3
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P08754 (Homo sapiens)
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Go to UniProtKB:  P08754
PHAROS:  P08754
GTEx:  ENSG00000065135 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP08754
Sequence Annotations
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1B [auth D]343Homo sapiensMutation(s): 0 
Gene Names: GNB1
UniProt & NIH Common Fund Data Resources
Find proteins for P62873 (Homo sapiens)
Explore P62873 
Go to UniProtKB:  P62873
PHAROS:  P62873
GTEx:  ENSG00000078369 
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UniProt GroupP62873
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2C [auth E]71Homo sapiensMutation(s): 0 
Gene Names: GNG2
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P59768 (Homo sapiens)
Explore P59768 
Go to UniProtKB:  P59768
PHAROS:  P59768
GTEx:  ENSG00000186469 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP59768
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  • Reference Sequence
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Entity ID: 4
MoleculeChains Sequence LengthOrganismDetailsImage
Extracellular calcium-sensing receptorD [auth A]939Homo sapiensMutation(s): 0 
Gene Names: CASRGPRC2APCAR1
Membrane Entity: Yes 
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Find proteins for P41180 (Homo sapiens)
Explore P41180 
Go to UniProtKB:  P41180
PHAROS:  P41180
GTEx:  ENSG00000036828 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP41180
Glycosylation
Glycosylation Sites: 3Go to GlyGen: P41180-1
Sequence Annotations
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  • Reference Sequence
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Entity ID: 5
MoleculeChains Sequence LengthOrganismDetailsImage
Extracellular calcium-sensing receptorE [auth B]959Homo sapiensMutation(s): 0 
Gene Names: CASRGPRC2APCAR1
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for P41180 (Homo sapiens)
Explore P41180 
Go to UniProtKB:  P41180
PHAROS:  P41180
GTEx:  ENSG00000036828 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP41180
Glycosylation
Glycosylation Sites: 3Go to GlyGen: P41180-1
Sequence Annotations
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  • Reference Sequence
Oligosaccharides

Help

Entity ID: 6
MoleculeChains Length2D Diagram Glycosylation3D Interactions
2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose
F, G, H
2N-Glycosylation
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Small Molecules
Ligands 6 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
PCW (Subject of Investigation/LOI)
Query on PCW

Download Ideal Coordinates CCD File 
I [auth A],
Q [auth B]
1,2-DIOLEOYL-SN-GLYCERO-3-PHOSPHOCHOLINE
C44 H85 N O8 P
SNKAWJBJQDLSFF-NVKMUCNASA-O
CLR (Subject of Investigation/LOI)
Query on CLR

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P [auth B]CHOLESTEROL
C27 H46 O
HVYWMOMLDIMFJA-DPAQBDIFSA-N
NAG
Query on NAG

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J [auth A],
R [auth B],
S [auth B]
2-acetamido-2-deoxy-beta-D-glucopyranose
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
TRP (Subject of Investigation/LOI)
Query on TRP

Download Ideal Coordinates CCD File 
M [auth A],
O [auth A],
V [auth B]
TRYPTOPHAN
C11 H12 N2 O2
QIVBCDIJIAJPQS-VIFPVBQESA-N
PO4 (Subject of Investigation/LOI)
Query on PO4

Download Ideal Coordinates CCD File 
N [auth A],
W [auth B]
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
CA (Subject of Investigation/LOI)
Query on CA

Download Ideal Coordinates CCD File 
K [auth A],
L [auth A],
T [auth B],
U [auth B]
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.50 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.20.1_4487:

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease (NIH/NIDDK)United States5R01DK132902-02

Revision History  (Full details and data files)

  • Version 1.0: 2024-02-07
    Type: Initial release
  • Version 1.1: 2024-02-21
    Changes: Database references
  • Version 1.2: 2024-03-13
    Changes: Database references