6L6R image
Deposition Date 2019-10-29
Release Date 2020-10-28
Last Version Date 2024-11-13
Entry Detail
PDB ID:
6L6R
Title:
Crystal structure of LRP6 E1E2-SOST complex
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
3.80 Å
R-Value Free:
0.25
R-Value Work:
0.20
R-Value Observed:
0.21
Space Group:
P 64
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Low-density lipoprotein receptor-related protein 6
Gene (Uniprot):LRP6
Chain IDs:A, B
Chain Length:622
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Sclerostin
Gene (Uniprot):SOST
Chain IDs:C, D
Chain Length:158
Number of Molecules:2
Biological Source:Homo sapiens
Primary Citation
Sclerostin inhibits Wnt signaling through tandem interaction with two LRP6 ectodomains.
Nat Commun 11 5357 5357 (2020)
PMID: 33097721 DOI: 10.1038/s41467-020-19155-4

Abstact

Low-density lipoprotein receptor-related protein 6 (LRP6) is a coreceptor of the β-catenin-dependent Wnt signaling pathway. The LRP6 ectodomain binds Wnt proteins, as well as Wnt inhibitors such as sclerostin (SOST), which negatively regulates Wnt signaling in osteocytes. Although LRP6 ectodomain 1 (E1) is known to interact with SOST, several unresolved questions remain, such as the reason why SOST binds to LRP6 E1E2 with higher affinity than to the E1 domain alone. Here, we present the crystal structure of the LRP6 E1E2-SOST complex with two interaction sites in tandem. The unexpected additional binding site was identified between the C-terminus of SOST and the LRP6 E2 domain. This interaction was confirmed by in vitro binding and cell-based signaling assays. Its functional significance was further demonstrated in vivo using Xenopus laevis embryos. Our results provide insights into the inhibitory mechanism of SOST on Wnt signaling.

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Primary Citation of related structures