This work was supported by grants from the Wellcome Trust and Royal Society (to M.Z.), the Institute of Molecular Biotechnology of Austria of the Austrian Academy of Sciences, the Austria Ministry of Sciences, the Austrian National Bank, and a European Union Framework 6 excellence grant (all to J.M.P.). We thank all members of the Zhao, Bourne and Penninger laboratories for discussions and technical assistance. Author Contributions M.Z. designed the experiments, took part in the cell migration and western blotting experiments, analysed the results and wrote the paper. J.M.P. designed the genetic analysis of the electric-field-induced signalling pathway, analysed the data and wrote the paper. B.S. did the in vivo experiments, most experiments with cells and tissues from transgenic mice. B.S. and J.P. did most of the cell migration and wound healing assays. T.W. performed the first signalling experiment and genotyping. B.R. performed the vibrating probe measurements. G.T., F.W. and P.W. did the experiments with HL60 cells. B.S., A.G. and Y.G. did the experiments on fibroblasts. P.N.D., A.S. and T.S. provided mouse and D. discoideum lines essential for the experiments. J.V.F., H.B. and C.D.M. helped with some of the experimental design, writing and analysis of the data. All authors discussed the results and commented on the manuscript.