A C-terminally truncated form of ?-catenin acts as a novel regulator of Wnt/?-catenin signaling in planarians.

ABSTRACT: ?-Catenin, the core element of the Wnt/?-catenin pathway, is a multifunctional and evolutionarily conserved protein which performs essential roles in a variety of developmental and homeostatic processes. Despite its crucial roles, the mechanisms that control its context-specific functions in time and space remain largely unknown. The Wnt/?-catenin pathway has been extensively studied in planarians, flatworms with the ability to regenerate and remodel the whole body, providing a 'whole animal' developmental framework to approach this question. Here we identify a C-terminally truncated ?-catenin (?-catenin4), generated by gene duplication, that is required for planarian photoreceptor cell specification. Our results indicate that the role of ?-catenin4 is to modulate the activity of ?-catenin1, the planarian ?-catenin involved in Wnt signal transduction in the nucleus, mediated by the transcription factor TCF-2. This inhibitory form of ?-catenin, expressed in specific cell types, would provide a novel mechanism to modulate nuclear ?-catenin signaling levels. Genomic searches and in vitro analysis suggest that the existence of a C-terminally truncated form of ?-catenin could be an evolutionarily conserved mechanism to achieve a fine-tuned regulation of Wnt/?-catenin signaling in specific cellular contexts.

SUBMITTER: Su H 

PROVIDER: S-EPMC5643146 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature