1. Optical cell biology group, Instituto Gulbenkian de Ciência, Oerias, Portugal
2. MRC Laboratory for Molecular Cell Biology, University College London, London, UK
3. Aix Marseille Université, CNRS, INP UMR7051, NeuroCyto, Marseille, France
4. HHMI Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA