R-spondin-1 (roof plate-specific spondin-1, hRspo1, RSPO1)

Function

• activator of the beta-catenin signaling cascade
• TCF-dependent gene activation
• role in Wnt/beta-catenin-dependent pathway
  • via a direct interaction with Wnt proteins
• role in Wnt-independent beta catenin pathway
• acts as a ligand for frizzled FZD8 & LRP6
• may negatively regulate the TGF-beta pathway
• interacts with the extracelular domain of FZD8 & LRP6 (does NOT form a ternary complex)
• interacts with WNT1
• binds heparin
• FU repeats required for activation & stabilization of beta-catenin
• upon injection into mice, induces rapid onset of crypt cell proliferation involving beta-catenin stabilization
• efficacy in a model of chemotherapy-induced intestinal mucositis

Compartment

secreted

Alternative splicing

named isoforms=2

More general terms

• R-spondin (roof plate-specific spondin)
• secreted protein
• glycoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/Q2MKA7.html