Fig. 5
DDX3X and metastasis. Rac1 protects β-catenin from degradation by enhancing β-catenin phosphorylation on S675. DDX3X facilitates Rac1 translation to stabilize β-catenin. Additionally, DDX3X might modulate cell-cell adhesions by enhancing Rac1-dependent E-cadherin endocytosis. Moreover, DDX3X directly binds to the E-cadherin promoter to suppress its expression. The decrease in E-cadherin expression causes β-catenin to be released from the cell membrane. The accumulated β-catenin translocates to the nucleus and interacts with TCF4 to increase the expression of its downstream target genes. In the nucleus, DDX3X activates the transcription factor YY1 with the help of circRNA circ-CTNNB1, leading to subsequent activation of genes involved in WNT/β-catenin signalling