1 Centre de Recherche en Biologie cellulaire de Montpellier (CRBM), UMR 5237 CNRS, Université Montpellier, 1919 Route de Mende, Cedex 5, Montpellier 34293, France; Institut de Biologie Computationnelle, Montpellier, France. Electronic address: andrey.kajava@crbm.cnrs.fr.
2 Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy; CNR Institute of Neuroscience, I-35121 Padova, Italy.