Inhibits the Wnt/Wingless pathway by binding to CTNNB1/beta-catenin and inhibiting beta-catenin-mediated transcriptional activation through competition with TCF/LEF transcription factors. Has also been shown to play a role in regulating the intracellular trafficking of polycystin-2/PKD2 and possibly of other intracellular proteins. Promotes adipocyte and cardiomyocyte differentiation.
Here we report a conserved nuclear protein, named chibby, which was identified in a screen for proteins that directly interact with the c-terminal region of beta-catenin. In mammalian cultured cells we demonstrate that chibby inhibits beta-catenin-mediated transcriptional activation by competing with lef-1 to bind to beta-catenin.