Caseine Kinase 1 alpha belongs is a member of the protein kinase superfamily, CK1 Ser/Thr protein kinase family, Casein kinase I subfamily. The CK1 isoforms - alpha, beta, gamma, delta, epsilon and their splice variants are involved in diverse cellular processes including membrane trafficking, circadian rhythm, cell cycle progression, chromosome segregation, apoptosis and cellular differentiation. Possibly CSNK1A1 can phosphorylate a large number of proteins and is involved in Wnt signaling where it phosphorylates CTNNB1 on Ser45. CSNK1A1 also interacts with the Axin complex.