Glinka A, Dolde C, Kirsch N, Huang YL, Kazanskaya O, Ingelfinger D, Boutros M, Cruciat CM, Niehrs C. LGR4 and LGR5 are R-spondin receptors mediating Wnt/β-catenin and Wnt/PCP signalling.
EMBO Rep 2011;
12:1055-61. [PMID:
21909076 DOI:
10.1038/embor.2011.175]
[Citation(s) in RCA: 452] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 08/08/2011] [Accepted: 08/10/2011] [Indexed: 12/27/2022] Open
Abstract
R-spondins are secreted Wnt signalling agonists, which regulate embryonic patterning and stem cell proliferation, but whose mechanism of action is poorly understood. Here we show that R-spondins bind to the orphan G-protein-coupled receptors LGR4 and LGR5 by their Furin domains. Gain- and loss-of-function experiments in mammalian cells and Xenopus embryos indicate that LGR4 and LGR5 promote R-spondin-mediated Wnt/β-catenin and Wnt/PCP signalling. R-spondin-triggered β-catenin signalling requires Clathrin, while Wnt3a-mediated β-catenin signalling requires Caveolin-mediated endocytosis, suggesting that internalization has a mechanistic role in R-spondin signalling.
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