Description
β-catenins are cytoplasmic proteins that are ubiquitously expressed. These proteins associate with E-cadherin at cellular junctions. β-catenin interacts with TCF and LEF transcription factors and is an essential member of the Wingless-Wnt signal transduction pathway. The adenomatous polyposis coli (APC) tumor-suppressor protein, together with Axin and GSK3β, form a Wnt-regulated signaling complex that mediates phosphorylation-dependent degradation of β-catenin by the proteasome. APC and Siah-1 mediate a novel β-catenin degradation pathway linking p53 activation to cell cycle control. Activating mutations in the human β-catenin gene have been found in human colon cancer and melanomas