CTNNB1 (catenin β-1, also known as β-catenin) plays a dual role in the cell. It is the key effector of WNT/CTNNB1 signalling, acting as a transcriptional co-activator of TCF/LEF target genes. It is also crucial for cell adhesion and a critical component of cadherin-based adherens junctions. Two functional pools of CTNNB1, a transcriptionally active and an adhesive pool, can therefore be distinguished. Whether cells merely balance the distribution of available CTNNB1 between these functional pools or whether interplay occurs between them has long been studied and debated. While interplay has been indicated upon artificial modulation of cadherin expression levels and during epithelial–mesenchymal transition, it is unclear to what extent CTNNB1 exchange occurs under physiological conditions and in response to WNT stimulation. Here, we review the available evidence for both of these models, discuss how CTNNB1 binding to its many interaction partners is controlled and propose avenues for future studies.

CTNNB1（连环蛋白β-1，也称为β-连环蛋白）在细胞中发挥双重作用。它是 WNT/CTNNB1 信号传导的关键效应子，充当 TCF/LEF 靶基因的转录共激活子。它对于细胞粘附也至关重要，并且是基于钙粘蛋白的粘附连接的关键组成部分。因此，可以区分 CTNNB1 的两个功能池，即转录活性池和粘附池。细胞是否只是平衡这些功能池之间可用的 CTNNB1 的分布，或者它们之间是否发生相互作用，长期以来一直在研究和争论。虽然在人工调节钙粘蛋白表达水平和上皮-间质转化过程中已显示出相互作用，但尚不清楚在生理条件下和响应 WNT 刺激时 CTNNB1 交换发生的程度。在这里，我们回顾了这两种模型的现有证据，讨论了如何控制 CTNNB1 与其许多相互作用伙伴的结合，并提出了未来研究的途径。