9.A.14.16.1
Frizzled-1, FZD1 of 647 aas and 8 to 11 TMSs with 1 - 4 TMSs near the N-terminus, and 7 TMSs near the C-terminus. 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 and activation of Wnt target genes. A second signaling pathway involving PKC and calcium fluxes has been seen for some family members. Association of Frizzled-6 from Drosophila melanogaster with CELSR1 (see TC# 9.A.14.6.4) is important, enabling efficient Frizzled-6 delivery to the cell surface, providing a quality-control mechanism that ensures appropriate stoichiometry of these two planar cell polarity (PCP) proteins at cell boundaries (Tang et al. 2020).