title: Molecular profiling of synaptic vesicle docking sites reveals novel proteins but few differences between glutamatergic and GABAergic synapses.
abstract: Neurotransmission involves calcium-triggered fusion of docked synaptic vesicles at specialized presynaptic release sites. While many of the participating proteins have been identified, the molecular composition of these sites has not been characterized comprehensively. Here, we report a procedure to biochemically isolate fractions highly enriched in docked synaptic vesicles. The fraction is largely free of postsynaptic proteins and most other organelles while containing most known synaptic vesicle and active zone proteins. Numerous presynaptic transmembrane proteins were also identified, together with over 30 uncharacterized proteins, many of which are evolutionarily conserved. Quantitative proteomic comparison of glutamate- and GABA-specific docking complexes revealed that, except of neurotransmitter-specific enzymes and transporters, only few proteins were selectively enriched in either fraction. We conclude that the core machinery involved in vesicle docking and exocytosis does not show compositional differences between the two types of synapses.
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Boyken
authors.forename: Mads
authors.initials: M
authors.lastname: Grønborg
authors.forename: Dietmar
authors.initials: D
authors.lastname: Riedel
authors.forename: Henning
authors.initials: H
authors.lastname: Urlaub
authors.forename: Reinhard
authors.initials: R
authors.lastname: Jahn
authors.forename: John Jia En
authors.initials: JJ
authors.lastname: Chua
mesh_terms: D000818:Animals; D001921:Brain / Q000648:ultrastructure; D018698:Glutamic Acid / Q000378:metabolism*; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000378:metabolism*; D017729:Presynaptic Terminals / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D040901:Proteomics; D051381:Rats; D013569:Synapses / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000187:drug effects / Q000378:metabolism*; D014357:Trypsin / Q000494:pharmacology; D033921:Vesicular Transport Proteins / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D033921:Vesicular Transport Proteins; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D014357:Trypsin