1 Max Planck Institute of Experimental Medicine, Göttingen, Germany; Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), Munich, Germany. Electronic address: msimons@gwdg.de.
2 Department of Cell Biology, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, United States. Electronic address: bwinckler@virginia.edu.