Receptor for Wnt proteins. Most frizzled receptors are coupled to the beta-catenin canonical signaling pathway, which leads to the activation of disheveled proteins, inhibition of GSK-3 kinase, nuclear accumulation of beta-catenin and activation of Wnt target genes. 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. Activation by WNT8 induces expression of beta-catenin target genes (By similarity). Following ligand activation, binds to CCDC88C/DAPLE which displaces DVL1 from FZD7 and leads to inhibition of canonical Wnt signaling, activation of G-proteins by CCDC88C and triggering of non-canonical Wnt responses (PubMed:26126266). May be involved in transduction and intercellular transmission of polarity information during tissue morphogenesis and/or in differentiated tissues. (Microbial infection) Acts as a receptor for C.difficile toxin TcdB in the colonic epithelium. Interacts with MAGI3 (By similarity). Interacts with DVL1 (By similarity). Interacts with CCDC88C/DAPLE; the interaction displaces DVL1 from FZD7, leading to inhibition of canonical Wnt signaling and triggering of non-canonical Wnt responses (PubMed:26126266). Interacts with MYOC (PubMed:19188438). Binds to SDCBP; this interaction is increased by inositol trisphosphate (IP3) (PubMed:27386966). Interacts with glypican GPC3 (PubMed:24496449). (Microbial infection) Interacts with C.difficile toxin TcdB; frizzled receptors constitute the major host receptors for TcdB in the colonic epithelium. Associated to the plasma membrane in the presence of FZD7 and phosphatidylinositol 4,5-bisphosphate (PIP2). Localized in recycling endosomes in other conditions. High expression in adult skeletal muscle and fetal kidney, followed by fetal lung, adult heart, brain, and placenta. Specifically expressed in squamous cell esophageal carcinomas. Lys-Thr-X-X-X-Trp motif interacts with the PDZ domain of Dvl (Disheveled) family members and is involved in the activation of the Wnt/beta-catenin signaling pathway. The FZ domain is involved in binding with Wnt ligands. Ubiquitinated by ZNRF3, leading to its degradation by the proteasome. Belongs to the G-protein coupled receptor Fz/Smo family.