Fig. 1

Wnt/β-catenin signaling pathway mechanism. Under normal physiological conditions, cytoplasmic β-catenin is phosphorylated by a destruction complex composed of APC, AXIN, GSK3β, CK1α, and the E3 ubiquitin ligase β-TrCP. In this degradation complex, GSK3β and CK1α mediate the phosphorylation of β-catenin, leading to its ubiquitination and subsequent proteasomal degradation. In the presence of Wnt binding, the FZD receptor is activated, which subsequently recruits DVL to the plasma membrane. DVL then interacts with AXIN, leading to the recruitment and accumulation of a complex at the receptor site. This receptor complex inhibits the activity of the β-catenin destruction complex (DC). As a result, β-catenin accumulates in the cytoplasma and is then transported to the nucleus, where it accumulates and interacts with TCF/LEF and coactivators to activate Wnt target genes