Receptor for Wnt proteins (PubMed:11092808, PubMed:18230341). Can activate WNT2, WNT10B, WNT5A, but not WNT2B or WNT4 (in vitro); the in vivo situation may be different since not all of these are known to be coexpressed (PubMed:11092808). In neurons, activation of WNT7A promotes formation of synapses (By similarity). Functions in the canonical Wnt/beta-catenin signaling pathway (PubMed:18230341). The canonical Wnt/beta-catenin signaling pathway leads to the activation of disheveled proteins, inhibition of GSK-3 kinase, nuclear accumulation of beta-catenin and activation of Wnt target genes (PubMed:18230341). A second signaling pathway involving PKC and calcium fluxes has been seen for some family members, but it is not yet clear if it represents a distinct pathway or if it can be integrated in the canonical pathway, as PKC seems to be required for Wnt-mediated inactivation of GSK-3 kinase. Both pathways seem to involve interactions with G-proteins. May be involved in transduction and intercellular transmission of polarity information during tissue morphogenesis and/or in differentiated tissues (Probable). Plays a role in yolk sac angiogenesis and in placental vascularization (PubMed:11092808). Binding of unsaturated fatty acid molecules (via FZ domain) promotes homodimerization (via FZ domain). Interacts with WNT2B (By similarity). Interacts with WNT7A (PubMed:18230341, PubMed:20530549). Interacts with GOPC (PubMed:11520064). Localized at the plasma membrane and also found at the Golgi. Detected in hippocampus (at protein level) (PubMed:20530549). Expressed in eye, kidney, lung, chondrocytes, epithelial cells of the small intestine and gobelet cells of the colon (PubMed:8626800). Detected at low levels in neonate brain; expression levels increase steadily during the first four weeks after birth and show a further increase in adults (at protein level) (PubMed:20530549). Expressed in the yolk sac, placenta, eye and lung bud at 9.5 dpc. At 10.5 dpc, also expressed in the placental blood vessel of embryonic origin (PubMed:11092808). The PDZ-binding motif mediates interaction with GOPC. The FZ domain is involved in binding with Wnt ligands. Ubiquitinated by RNF43 and ZNRF3, leading to its degradation by the proteasome. Full embryonic lethality around 12.5 dpc, due to defects in yolk sac and placenta vascularization. Belongs to the G-protein coupled receptor Fz/Smo family.