Mouse R-spondin-1, RSPO1 ELI

Activator of the canonical Wnt signaling pathway by acting as a ligand for LGR4-6 receptors.

Upon binding to LGR4-6 (LGR4, LGR5 or LGR6), LGR4-6 associate with phosphorylated LRP6 and frizzled receptors that are activated by extracellular Wnt receptors, triggering the canonical Wnt signaling pathway to increase expression of target genes (PubMed: 21693646).

Also regulates the canonical Wnt/beta-catenin-dependent pathway and non-canonical Wnt signaling by acting as an inhibitor of ZNRF3, an important regulator of the Wnt signaling pathway.

Acts as a ligand for frizzled FZD8 and LRP6.

May negatively regulate the TGF-beta pathway.

Has a essential roles in ovary determination (By similarity).

Regulates Wnt signaling by antagonizing DKK1/KREM1-mediated internalization of LRP6 through an interaction with KREM1 (By similarity).