CCDC88C

Required for activation of guanine nucleotide-binding proteins (G proteins) during non-canonical Wnt signaling. Binds to ligand-activated Wnt receptor FZD7, displacing DVL1 from the FZD7 receptor and leading to inhibition of canonical Wnt signaling. Acts as a non-receptor guanine nucleotide exchange factor by also binding to guanine nucleotide-binding protein G(i) alpha (Gi-alpha) subunits, leading to their activation. Binding to Gi-alpha subunits displaces the beta and gamma subunits from the heterotrimeric G protein complex, triggering non-canonical Wnt responses such as activation of RAC1 and PI3K-AKT signaling. Promotes apical constriction of cells via ARHGEF18..

Function from UniProtKB (Q9P219), read 2026-09-23. CC BY 4.0.