Key regulator of cell-cell adhesion that associates with and regulates the cell adhesion properties of both C-, E- and N-cadherins, being critical for their surface stability. Beside cell-cell adhesion, regulates gene transcription through several transcription factors including ZBTB33/Kaiso2 and GLIS2, and the activity of Rho family GTPases and downstream cytoskeletal dynamics. Implicated both in cell transformation by SRC and in ligand-induced receptor signaling through the EGF, PDGF, CSF-1 and ERBB2 receptors. Required for gastrulation, axial elongation and development of the craniofacial skeleton and eye. Interacts with C-cadherin and with zbtb33. Ubiquitously expressed. Expressed maternally and throughout early embryogenesis. Highly expressed in tissues participating in prominent morphogenetic movements. Enriched in the animal hemisphere in early gastrula and the anterior region in late neurula. Expressed in the head region in the tailbud stage, particularly the optic vesicle, ear vesicle, olfactory placode and branchial arches. Expression is also weakly elevated in the somites, notochord and pronephros. ARM repeats 1 to 5 mediate interaction with cadherins. Belongs to the beta-catenin family.