1. Max Planck Institute of Molecular Cell Biology and Genetics 1 , Dresden D-01307 , Germany
2. Paul Langerhans Institute Dresden of the Helmholtz Center Munich at The University Hospital Carl Gustav Carus and Faculty of Medicine of the TU Dresden 2 , Dresden D-01307 , Germany
3. Cluster of Excellence Physics of Life, TU Dresden 3 , 01062 Dresden , Germany