frizzled-9; Fz-9; hFz9; FzE6; CD349 (FZD9, FZD3)

Function

• receptor for Wnt proteins
• most of 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 & activation of Wnt target genes
• a second signaling pathway involving PKC & Ca+2 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 & intercellular transmission of polarity information during tissue morphogenesis &/or in differentiated tissues

Structure

• Lys-Thr-X-X-X-Trp motif is involved in the activation of the Wnt/beta-catenin signaling pathway (putative)
• FZ domain is involved in binding with Wnt ligands
• belongs to the G-protein coupled receptor Fz/smo family
• contains 1 FZ (frizzled) domain

Compartment

• cell membrane

Expression

• expressed predominantly in adult & fetal brain, testis, eye, skeletal muscle & kidney
• moderately expressed in pancreas, thyroid, adrenal cortex, small intestine & stomach. detected in fetal liver & kidney

Pathology

• reference to Williams syndrome encountered (no verification)

Notes

• first described as FZD3 in literature

More general terms

• frizzled homolog protein
• glycoprotein
• CD antigen

Additional terms

• Williams-Beuren syndrome

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8326
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8326
• OMIM: https://mirror.omim.org/entry/601766
• UniProt: http://www.uniprot.org/uniprot/O00144.html