Key Laboratory of Carcinogenesis and Translational Research, Ministry of Education of China, Peking University Health Science Center, Beijing, China.
PLoS One. 2013 May 22;8(5):e63490. doi: 10.1371/journal.pone.0063490. Print 2013.
Kindlin 2, as an integrin-associated protein, is required for myocyte elongation and fusion. However, the association of Kindlin 2 with muscle differentiation-related signaling pathways is unknown. Here, we identified a mechanism that Kindlin 2 regulates myogenic regulatory factors myogenin via a canonical Wnt/β-catenin signaling. We found that knockdown of Kindlin 2 leads to the abolishment of β-catenin/TCF4-mediated transcription in C2C12 cells, followed by the impairment of myogenic differentiation. Mechanistically, nuclear translocation of both Kindlin 2 and β-catenin is induced during myogenic differentiation. In particular, Kindlin 2 forms a tripartite complex with active β-catenin and TCF4, and hence co-occupied on the promoter of myogenin to enhance its expression. Functionally, depletion of Kindlin 2 impairs myogenic differentiation via downregulation of myogenin. Taken together, our data reveal that Kindlin 2 is required for Wnt signaling-regulated myogenic differentiation, providing a mechanistic insight into the role of Kindlin-2 in muscle development.
Kindlin 2 作为整合素相关蛋白,对于心肌细胞的伸长和融合是必需的。然而,Kindlin 2 与肌肉分化相关信号通路的关联尚不清楚。在这里,我们确定了一种机制,Kindlin 2 通过经典的 Wnt/β-catenin 信号通路调节肌生成调节因子 myogenin。我们发现,Kindlin 2 的敲低导致 C2C12 细胞中β-catenin/TCF4 介导的转录被废除,随后肌发生分化受损。在机制上,Kindlin 2 和β-catenin 在肌发生分化过程中均被诱导发生核转位。特别是,Kindlin 2 与活性β-catenin 和 TCF4 形成三元复合物,并因此共同占据 myogenin 的启动子以增强其表达。功能上,Kindlin 2 的耗竭通过下调 myogenin 来损害肌发生分化。总之,我们的数据揭示了 Kindlin 2 对于 Wnt 信号调节的肌发生分化是必需的,为 Kindlin-2 在肌肉发育中的作用提供了机制上的见解。