LAUSR

b -Catenin, a 781–amino acid, 85.5-kDa scaffold protein, serves a range of molecular functions including cell-to-cell adhesion to gene transcription. It is highly evolutionarily conserved and indispensable for embryonic development. bCatenin is a binding partner of adenomatous polyposis coli protein, responsible for degrading b-catenin to prevent its nuclear accumulation and gene transcriptional function (Fig. 1A). Adenomatous polyposis coli is mutated in 80% of colon cancers and is the hereditary mutated gene in familial adenomatous polyposis disorder. b-Catenin is also important for liver development and carcinogenesis. As a key binding partner of Ecadherin in adherens junctions, b-catenin links the cytoskeleton of adjacent epithelial cells. How b-catenin carries out both cytoplasmic and nuclear functions, and the consequences of its dysregulation, remain a subject of much debate. In this original article by Thompson and colleagues, the authors describe a finely tuned interplay between b-catenin and farnesoid X receptor (FXR) in response to cholestatic injury.