Abstract：
Calpain2 is a conventional member of the non-lysosomal calpain protease family that has been shown to affect the dynamics of focal and cell-cell adhesions by proteolyzing the components of adhesion complexes. Here, we inactivated calpain2 using CRISPR/Cas9 in epithelial MDCK cells. We show that depletion of calpain2 has multiple effects on cell morphology and function. Calpain2-depleted cells develop epithelial shape, however, they cover a smaller area, and cell clusters are more compact. Inactivation of calpain2 enhanced restoration of transepithelial electrical resistance after calcium switch, decreased cell migration, and delayed cell scattering induced by HGF/SF. In addition, calpain2 depletion prevented morphological changes induced by ERK2 overexpression. Interestingly, proteolysis of several calpain2 targets, including E-cadherin, β-catenin, talin, FAK, and paxillin, was not discernibly affected by calpain2 depletion. Taken together, these data suggest that calpain2 regulates the stability of cell-cell and cell-substratum adhesions indirectly without affecting the proteolysis of these adhesion complexes.
摘要：
Calpain2是非溶酶体钙蛋白酶家族的常规成员，已显示通过蛋白水解粘附复合物的成分来影响病灶和细胞-细胞粘附的动力学。这里,我们使用CRISPR/Cas9在上皮MDCK细胞中灭活calpain2。我们发现calpain2的耗竭对细胞形态和功能有多重影响。Calpain2耗尽细胞发育上皮形状，然而,它们覆盖较小的区域，细胞簇更紧凑。钙蛋白酶2的失活增强了钙转换后跨上皮电阻的恢复，细胞迁移减少，和HGF/SF诱导的延迟细胞散射。此外,calpain2耗竭阻止了ERK2过表达诱导的形态变化。有趣的是,几个calpain2靶标的蛋白水解，包括E-cadherin,β-连环蛋白，塔林,FAK,和Paxillin,不受calpain2消耗的明显影响。一起来看,这些数据表明，calpain2间接调节细胞-细胞和细胞-基质粘附的稳定性，而不影响这些粘附复合物的蛋白水解。
