1. INSERM U.382, IBDM, Case 907 Luminy, 13288 Marseille Cedex 9, France.
2. Department of Neuroscience, Genentech, South San Francisco, CA 94080-4990, USA.
3. University of St. Andrews, St. Andrews, Fife, Scotland KY16 9AJ, United Kingdom.
4. Department of Cell Genetics, Genentech, South San Francisco, CA 94080-4990, USA.
5. Department of Protein Chemistry, Genentech, South San Francisco, CA 94080-4990, USA.
6. Departments of Pathology, Neurology, and Neuroscience and the Neuropathology Laboratory, Johns Hopkins University School of Medicine, Baltimore, MD 21208, USA.