β-Catenin is a multifunctional adaptor protein involved in cadherin-mediated cell–cell adhesion and in responding to the activation of several signal transduction pathways. CK1 phosphorylates β-catenin on Ser45. This phosphorylation event primes β-catenin for subsequent phosphorylation by GSK-3. GSK-3β destabilizes β-catenin by phosphorylating it at Ser33, Ser37 and Thr41.). Mutations in β-Catenin have been implicated in its accumulation and various forms of carcinomas.

1.Kikuchi A.;"Regulation of beta-catenin signaling in the Wnt pathway."; Biochem. Biophys. Res. Commun. 268:243-248(2000).
2.Dobrosotskaya I.Y., James G.L.; "MAGI-1 interacts with beta-catenin and is associated with cell-cell adhesion structures."; Biochem. Biophys. Res. Commun. 270:903-909(2000).
3.Kim J.-S., Crooks H., Dracheva T., Nishanian T.G., Singh B., Jen J., Waldman T.; "Oncogenic beta-catenin is required for bone morphogenetic protein 4 expression in human cancer cells."; Cancer Res. 62:2744-2748(2002).