1. Department of Microbiology, Immunology and Molecular Genetics; University of California; Los Angeles; CA; 90095-1489; USA
2. Pasarow Mass Spectrometry Laboratory; NPI-Semel Institute for Neuroscience and Human Behaviour; David Geffen School of Medicine; University of California; Los Angeles; CA; USA
3. UMR 5539; Centre National de la Recherche Scientifique; Université de Montpellier 2; Montpellier; France