Human Norrin, NDP ELI

Activates the canonical Wnt signaling pathway through FZD4 and LRP5 coreceptor.

Plays a central role in retinal vascularization by acting as a ligand for FZD4 that signals via stabilizing beta-catenin (CTNNB1) and activating LEF/TCF-mediated transcriptional programs.

Acts in concert with TSPAN12 to activate FZD4 independently of the Wnt-dependent activation of FZD4, suggesting the existence of a Wnt-independent signaling that also promote accumulation the beta-catenin (CTNNB1).

May be involved in a pathway that regulates neural cell differentiation and proliferation.

Possible role in neuroectodermal cell-cell interaction.