Anti-FAK (E393) Anticorps (A25830)

Myosin light chain kinase (MLCK) has long been implicated in the myosin phosphorylation and force generation required for cell migration. Here, we surprisingly found that the deletion of MLCK resulted in fast cell migration, enhanced protrusion formation, and no alteration of myosin light chain phosphorylation. The mutant cells showed reduced membrane tether force and fewer membrane F-actin filaments. This phenotype was rescued by either kinase-dead MLCK or five-DFRXXL motif, a MLCK fragment with potent F-actin-binding activity. Pull-down and co-immunoprecipitation assays showed that the absence of MLCK led to attenuated formation of transmembrane complexes, including myosin II, integrins and fibronectin. We suggest that MLCK is not required for myosin phosphorylation in a migrating cell. A critical role of MLCK in cell migration involves regulating the cell membrane tension and protrusion necessary for migration, thereby stabilizing the membrane skeleton through F-actin-binding activity. This finding sheds light on a novel regulatory mechanism of protrusion during cell migration.

The phosphatase and tensin homolog (PTEN) gene, an important tumor-suppressor gene, has been demonstrated to have the potential for inhibiting proliferation, migration and invasion in various types of cancer cells. The aim of the present study was to investigate the effect of PTEN expression on osteosarcoma (OS) cells. The wild-type PTEN plasmid was transfected into OS U2-OS cells. The effects of PTEN on the adhesion, migration and invasion of U2-OS cells were evaluated by cell adhesion analysis, in vitro scratch and Transwell assays, respectively. The levels of MMP-2 and MMP-9, and focal adhesion kinase (FAK) protein regulated by PTEN were detected via western blot analysis. Meanwhile, the level of intracellular FAK phosphorylation was observed. The results from the present study showed that overexpression of PTEN transcription and protein were observed in U2-OS cells following PTEN transfection. Furthermore, the migration, invasion and adhesion capabilities of the cells with PTEN transfection were significantly decreased compared to these capacities in the cells without PTEN. Meanwhile, it was shown that there was downregulation of MMP-9, FAK and p-FAK concomitant with the elevation of the intracellular PTEN level. It is therefore evident that the upregulation of PTEN may attenuate the adhesion, migration and invasion capabilities of OS cells. The mechanisms of the effects of PTEN on OS cells may be correlated with a reduction in the related genes by PTEN regulation.