Multitasking β-catenin: from adhesion and transcription to RNA regulation

beta-Catenin is an evolutionally conserved protein which orchestrates myriad biological processes by regulating Wnt signaling and cell adhesion. The importance of the dual roles of beta-catenin protein (signaling and structural) is highlighted throughout the development and adult life of all metazoan animals. beta-Catenin is located in the cadherin-based adherent junctions in the plasma membrane of epithelial cells; upon Wnt activation, it accumulates and translocates to the nucleus in order to activate transcription. Thus, mutations in beta-catenin and the components of the Wnt signal transduction pathway underline the aberrant activation of Wnt/beta-catenin signaling in human diseases and cancers. In this review, we briefly summarize the core functions of beta-catenin relevant to Wnt signaling and adhesion and introduce the additional and novel role of beta-catenin related to the regulation of RiboNucleoAcid (RNA) metabolism. Such multiple functions of beta-catenin can be understood by examining its structure and complex with the plethora of interacting proteins. Also, molecular evolution analysis has been used to understand the origin of multifunctionality of beta-catenin. We will also discuss the newly identified role of beta-catenin as an RNA-binding protein and as a regulator of RNA stability and splicing. It is hoped that future research will shed light on any unexpected findings by clarifying the RNA-mediated mechanism of beta-catenin and the implication to Wnt-regulated pathogenesis.