β-Catenin monoclonal antibody (12F7)

β-Catenin, a vertebrate homologue of Drosophila armadillo encoded by the CTNNB1 gene, performs two functions in the cell: mediating cell-cell adhesion by association between E-cadherin and the cytoskeleton, and acting as a downstream transcriptional activator of Wnt signaling, a key player in such functions as embryonic development, the induction of cell polarity, and the determination of cell fate.  In the absence of Wnt signaling, glycogen synthase kinase-3β (GSK-3β) phosphorylates any free β-catenin at the amino terminus.  This results in adenomatous polyposis coli tumor suppressor protein (APC)-mediated β-catenin degradation via the ubiquitin-proteosome pathway.  Wnt signaling stabilizes β-catenin by inhibiting the activity of GSK-3β and preventing β-catenin degradation.  β-catenin forms complexes with DNA-binding proteins such as T-cell factor (Tcf) and lymphocyte-enhancer factor (Lef), which promote  expression of a variety of target genes, including c-myc and cyclin D1.