b-catenin is a component of both the cadherin cell adhesion system and the Wnt signaling pathway. Wnt signaling increases the amount of b-catenin, by preventing its ubiquitination and degradation, allowing its direct interaction with transcription factors of the lymphoid enhancer factor-T cell factor family and modulation of gene expression. Axin is involved in the degradation of b-catenin by acting as a scaffold to form a complex between b-catenin, adenomatous polyposis coli (APC) and GSK-3b. APC, which is phosphorylated by GSK-3b, induces degradation of b-catenin, thus inhibiting Wnt signal transduction. Conductin is 45% identical to axin and appears to play a similar role to axin in the Wnt signaling pathway.
