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.

Department of Interdisciplinary Oncology Louisiana State University HSC School of Medicine New Orleans USA

Laboratory of Cell Signalling Institute of Microbiology of the Czech Academy of Sciences 142 00 Prague Czech Republic

Laboratory of Cell Signalling Institute of Microbiology of the Czech Academy of Sciences 142 00 Prague Czech Republic; Department of Cell Biology Faculty of Science Charles University Prague Czech Republic

Laboratory of Viral and Cellular Genetics and Laboratory of Integrative Biology Institute of Molecular Genetics of the Czech Academy of Sciences 142 20 Prague Czech Republic

References provided by Crossref.org