Canonical Wnt Pathway

Wnt pathways are involved in the control of gene expression, cell behavior, cell adhesion, and cell polarity. The Canonical (β-Catenin-Dependent) Wnt Signaling pathway is the best studied of the Wnt pathways and is highly conserved through evolution. In this pathway, Wnt signaling inhibits the degradation of β-catenin, which can regulate transcription of a number of genes. Wnt signaling is activated via ligation of Wnt proteins to their respective dimeric cell surface receptors composed of the seven transmembrane frizzled proteins and the LRP5/6. Upon ligation to their receptors, the cytoplasmic protein disheveled (Dvl) is recruited, phosphorylated and activated. Activation of Dvl induces the dissociation of GSK-3β from Axin and leads to the inhibition of GSK-3β. Next, the phosphorylation and degradation of β-catenin is inhibited as a result of the inactivation of the "destruction complex". Subsequently, stabilized β-catenin translocates into the nucleus leading to changes in different target gene expressions.