Unbound MEDLINE

ZNRF3 promotes Wnt receptor turnover in an R-spondin-sensitive manner.

Abstract

R-spondin proteins strongly potentiate Wnt signalling and function as stem-cell growth factors. Despite the biological and therapeutic significance, the molecular mechanism of R-spondin action remains unclear. Here we show that the cell-surface transmembrane E3 ubiquitin ligase zinc and ring finger 3 (ZNRF3) and its homologue ring finger 43 (RNF43) are negative feedback regulators of Wnt signalling. ZNRF3 is associated with the Wnt receptor complex, and inhibits Wnt signalling by promoting the turnover of frizzled and LRP6. Inhibition of ZNRF3 enhances Wnt/β-catenin signalling and disrupts Wnt/planar cell polarity signalling in vivo. Notably, R-spondin mimics ZNRF3 inhibition by increasing the membrane level of Wnt receptors. Mechanistically, R-spondin interacts with the extracellular domain of ZNRF3 and induces the association between ZNRF3 and LGR4, which results in membrane clearance of ZNRF3. These data suggest that R-spondin enhances Wnt signalling by inhibiting ZNRF3. Our study provides new mechanistic insights into the regulation of Wnt receptor turnover, and reveals ZNRF3 as a tractable target for therapeutic exploration.

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  • Authors

    Hao HX, Xie Y, Zhang Y, Charlat O, Oster E, Avello M, Lei H, Mickanin C, Liu D, Ruffner H, Mao X, Ma Q, Zamponi R, Bouwmeester T, Finan PM, Kirschner MW, Porter JA, Serluca FC, Cong F

    Institution

    Novartis Institutes for Biomedical Research, 250 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.

    Source

    Nature 485:7397 2012 May 10 pg 195-200

    MeSH

    Animals
    Cell Polarity
    Colorectal Neoplasms
    DNA-Binding Proteins
    Feedback, Physiological
    Female
    Frizzled Receptors
    HEK293 Cells
    Humans
    Low Density Lipoprotein Receptor-Related Protein-6
    Male
    Mice
    Mice, Knockout
    Oncogene Proteins
    Protein Stability
    Protein Structure, Tertiary
    Receptors, G-Protein-Coupled
    Receptors, Wnt
    Thrombospondins
    Ubiquitin-Protein Ligases
    Ubiquitination
    Wnt Signaling Pathway
    Xenopus
    Zebrafish
    beta Catenin

    Pub Type(s)

    Journal Article

    Language

    eng

    PubMed ID

    22575959