1. Department of Cell Biology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain
2. Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, 28031 Madrid, Spain
3. Present address: Francis Crick Institute, Mill Hill Laboratory, Mill Hill, London NW7 1AA, United Kingdom
4. Present address: Department of Cell Biology and Human Anatomy, University of California Davis, 95616 Davis, California, USA
5. Vall d´Hebron Institute of Research, Barcelona 08035, Spain
6. Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona 08010, Spain