Structure of the Wnt-Frizzled-LRP6 Initiation Complex Reveals the Basis for Coreceptor Discrimination

Overview

Journal Proc Natl Acad Sci U S A

Specialty Science

Date 2023 Mar 9

PMID 36893265

Authors

Naotaka Tsutsumi

Sunhee Hwang

Deepa Waghray

Simon Hansen

Kevin M Jude

Nan Wang

Yi Miao

Caleb R Glassman

Nathanael A Caveney

Claudia Y Janda

Rami N Hannoush

K Christopher Garcia

Affiliations

Soon will be listed here.

Abstract

Wnt morphogens are critical for embryonic development and tissue regeneration. Canonical Wnts form ternary receptor complexes composed of tissue-specific Frizzled (Fzd) receptors together with the shared LRP5/6 coreceptors to initiate β-catenin signaling. The cryo-EM structure of a ternary initiation complex of an affinity-matured XWnt8-Frizzled8-LRP6 complex elucidates the basis of coreceptor discrimination by canonical Wnts by means of their N termini and linker domains that engage the LRP6 E1E2 domain funnels. Chimeric Wnts bearing modular linker "grafts" were able to transfer LRP6 domain specificity between different Wnts and enable non-canonical Wnt5a to signal through the canonical pathway. Synthetic peptides comprising the linker domain serve as Wnt-specific antagonists. The structure of the ternary complex provides a topological blueprint for the orientation and proximity of Frizzled and LRP6 within the Wnt cell surface signalosome.

Citing Articles

Signaling pathway mechanisms of circadian clock gene Bmal1 regulating bone and cartilage metabolism: a review.

Ze Y, Wu Y, Tan Z, Li R, Li R, Gao W Bone Res. 2025; 13(1):19.

PMID: 39870641 PMC: 11772753. DOI: 10.1038/s41413-025-00403-6.

Mechanistic insights into Wnt-β-catenin pathway activation and signal transduction.

Maurice M, Angers S Nat Rev Mol Cell Biol. 2025; .

PMID: 39856369 DOI: 10.1038/s41580-024-00823-y.

The co-receptor Tetraspanin12 directly captures Norrin to promote ligand-specific β-catenin signaling.

Bruguera E, Mahoney J, Weis W Elife. 2025; 13.

PMID: 39745873 PMC: 11695057. DOI: 10.7554/eLife.96743.

Challenging Reported Frizzled-Targeting Compounds in Selective Assays Reveals Lack of Functional Inhibition and Claimed Profiles.

Koval A, Boudou C, Katanaev V ACS Pharmacol Transl Sci. 2024; 7(12):4144-4154.

PMID: 39698282 PMC: 11650735. DOI: 10.1021/acsptsci.4c00570.

Structural and Functional Insights into Dishevelled-Mediated Wnt Signaling.

Wang L, Zhu R, Wen Z, Fan H, Norwood-Jackson T, Jathan D Cells. 2024; 13(22).

PMID: 39594618 PMC: 11592973. DOI: 10.3390/cells13221870.

References

Matoba K, Mihara E, Tamura-Kawakami K, Miyazaki N, Maeda S, Hirai H . Conformational Freedom of the LRP6 Ectodomain Is Regulated by N-glycosylation and the Binding of the Wnt Antagonist Dkk1. Cell Rep. 2017; 18(1):32-40. DOI: 10.1016/j.celrep.2016.12.017. View

Stanger K, Steffek M, Zhou L, Pozniak C, Quan C, Franke Y . Allosteric peptides bind a caspase zymogen and mediate caspase tetramerization. Nat Chem Biol. 2012; 8(7):655-60. DOI: 10.1038/nchembio.967. View

Punjani A, Rubinstein J, Fleet D, Brubaker M . cryoSPARC: algorithms for rapid unsupervised cryo-EM structure determination. Nat Methods. 2017; 14(3):290-296. DOI: 10.1038/nmeth.4169. View

Winkler D, Sutherland M, Geoghegan J, Yu C, Hayes T, Skonier J . Osteocyte control of bone formation via sclerostin, a novel BMP antagonist. EMBO J. 2003; 22(23):6267-76. PMC: 291840. DOI: 10.1093/emboj/cdg599. View

Zhang X, MacDonald B, Gao H, Shamashkin M, Coyle A, Martinez R . Characterization of Tiki, a New Family of Wnt-specific Metalloproteases. J Biol Chem. 2015; 291(5):2435-43. PMC: 4732225. DOI: 10.1074/jbc.M115.677807. View

Sima J, Piao Y, Chen Y, Schlessinger D . Molecular dynamics of Dkk4 modulates Wnt action and regulates meibomian gland development. Development. 2016; 143(24):4723-4735. PMC: 5201035. DOI: 10.1242/dev.143909. View

Clevers H, Loh K, Nusse R . Stem cell signaling. An integral program for tissue renewal and regeneration: Wnt signaling and stem cell control. Science. 2014; 346(6205):1248012. DOI: 10.1126/science.1248012. View

Jumper J, Evans R, Pritzel A, Green T, Figurnov M, Ronneberger O . Highly accurate protein structure prediction with AlphaFold. Nature. 2021; 596(7873):583-589. PMC: 8371605. DOI: 10.1038/s41586-021-03819-2. View

Sanchez-Garcia R, Gomez-Blanco J, Cuervo A, Carazo J, Sorzano C, Vargas J . DeepEMhancer: a deep learning solution for cryo-EM volume post-processing. Commun Biol. 2021; 4(1):874. PMC: 8282847. DOI: 10.1038/s42003-021-02399-1. View

10.

Cho C, Wang Y, Smallwood P, Williams J, Nathans J . Molecular determinants in Frizzled, Reck, and Wnt7a for ligand-specific signaling in neurovascular development. Elife. 2019; 8. PMC: 6588345. DOI: 10.7554/eLife.47300. View

11.

Xu Q, Wang Y, Dabdoub A, Smallwood P, Williams J, Woods C . Vascular development in the retina and inner ear: control by Norrin and Frizzled-4, a high-affinity ligand-receptor pair. Cell. 2004; 116(6):883-95. DOI: 10.1016/s0092-8674(04)00216-8. View

12.

Liebschner D, Afonine P, Baker M, Bunkoczi G, Chen V, Croll T . Macromolecular structure determination using X-rays, neutrons and electrons: recent developments in Phenix. Acta Crystallogr D Struct Biol. 2019; 75(Pt 10):861-877. PMC: 6778852. DOI: 10.1107/S2059798319011471. View

13.

Painter J, Merritt E . Optimal description of a protein structure in terms of multiple groups undergoing TLS motion. Acta Crystallogr D Biol Crystallogr. 2006; 62(Pt 4):439-50. DOI: 10.1107/S0907444906005270. View

14.

Chesnut J, Baytan A, Russell M, Chang M, Bernard A, Maxwell I . Selective isolation of transiently transfected cells from a mammalian cell population with vectors expressing a membrane anchored single-chain antibody. J Immunol Methods. 1996; 193(1):17-27. DOI: 10.1016/0022-1759(96)00032-4. View

15.

Bepler T, Morin A, Rapp M, Brasch J, Shapiro L, Noble A . Positive-unlabeled convolutional neural networks for particle picking in cryo-electron micrographs. Nat Methods. 2019; 16(11):1153-1160. PMC: 6858545. DOI: 10.1038/s41592-019-0575-8. View

16.

Nile A, Hannoush R . Fatty acylation of Wnt proteins. Nat Chem Biol. 2016; 12(2):60-9. DOI: 10.1038/nchembio.2005. View

17.

Tan Y, Baldwin P, Davis J, Williamson J, Potter C, Carragher B . Addressing preferred specimen orientation in single-particle cryo-EM through tilting. Nat Methods. 2017; 14(8):793-796. PMC: 5533649. DOI: 10.1038/nmeth.4347. View

18.

Chang T, Hsieh F, Zebisch M, Harlos K, Elegheert J, Jones E . Structure and functional properties of Norrin mimic Wnt for signalling with Frizzled4, Lrp5/6, and proteoglycan. Elife. 2015; 4. PMC: 4497409. DOI: 10.7554/eLife.06554. View

19.

Janda C, Waghray D, Levin A, Thomas C, Garcia K . Structural basis of Wnt recognition by Frizzled. Science. 2012; 337(6090):59-64. PMC: 3577348. DOI: 10.1126/science.1222879. View

20.

Hirai H, Matoba K, Mihara E, Arimori T, Takagi J . Crystal structure of a mammalian Wnt-frizzled complex. Nat Struct Mol Biol. 2019; 26(5):372-379. DOI: 10.1038/s41594-019-0216-z. View