protein_function: Activator of the canonical Wnt signaling pathway byacting as a ligand for LGR4-6 receptors. Upon binding to LGR4-6(LGR4, LGR5 or LGR6), LGR4-6 associate with phosphorylated LRP6and frizzled receptors that are activated by extracellular Wntreceptors, triggering the canonical Wnt signaling pathway toincrease expression of target genes. Also regulates the canonicalWnt,beta-catenin-dependent pathway and non-canonical Wnt signalingby acting as an inhibitor of ZNRF3, an important regulator of theWnt signaling pathway..
R-spondin 4 is a protein in humans that is encoded by the RSPO4 gene. It is mapped to chromosome 20p13. This gene encodes a member of the R-spondin family of proteins that share a common domain organization consisting of a signal peptide, cysteine-rich,furin-like domain, thrombospondin domain and a C-terminal basic region. The encoded protein may be involved in activation of Wnt,beta-catenin signaling pathways. Mutations in this gene are associated with anonychia congenital. Alternate splicing results in multiple transcript variants.
