title: Proteomic Analysis of Unbounded Cellular Compartments: Synaptic Clefts.
abstract: Cellular compartments that cannot be biochemically isolated are challenging to characterize. Here we demonstrate the proteomic characterization of the synaptic clefts that exist at both excitatory and inhibitory synapses. Normal brain function relies on the careful balance of these opposing neural connections, and understanding how this balance is achieved relies on knowledge of their protein compositions. Using a spatially restricted enzymatic tagging strategy, we mapped the proteomes of two of the most common excitatory and inhibitory synaptic clefts in living neurons. These proteomes reveal dozens of synaptic candidates and assign numerous known synaptic proteins to a specific cleft type. The molecular differentiation of each cleft allowed us to identify Mdga2 as a potential specificity factor influencing Neuroligin-2's recruitment of presynaptic neurotransmitters at inhibitory synapses.
authors: Department of Chemistry, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors: Ken H
authors: KH
authors: Loh
authors: Department of Chemistry, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors: Philipp S
authors: PS
authors: Stawski
authors: Department of Chemistry, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
authors: Austin S
authors: AS
authors: Draycott
authors: Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
authors: Namrata D
authors: ND
authors: Udeshi
authors: F.M. Kirby Neurobiology Center, Boston Children's Hospital (BCH) and Harvard Medical School (HMS), Boston, MA 02115, USA.
authors: Emily K
authors: EK
authors: Lehrman
authors: F.M. Kirby Neurobiology Center, Boston Children's Hospital (BCH) and Harvard Medical School (HMS), Boston, MA 02115, USA.
authors: Daniel K
authors: DK
authors: Wilton
authors: Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
authors: Tanya
authors: T
authors: Svinkina
authors: National Center for Microscopy and Imaging Research, University of California at San Diego, La Jolla, CA 92093 USA; Department of Neurosciences, University of California at San Diego, La Jolla, CA 92093, USA.
authors: Thomas J
authors: TJ
authors: Deerinck
authors: National Center for Microscopy and Imaging Research, University of California at San Diego, La Jolla, CA 92093 USA; Department of Neurosciences, University of California at San Diego, La Jolla, CA 92093, USA.
authors: Mark H
authors: MH
authors: Ellisman
authors: F.M. Kirby Neurobiology Center, Boston Children's Hospital (BCH) and Harvard Medical School (HMS), Boston, MA 02115, USA.
authors: Beth
authors: B
authors: Stevens
authors: Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA.
authors: Steven A
authors: SA
authors: Carr
authors: Department of Chemistry, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. Electronic address: ayting@stanford.edu.
authors: Alice Y
authors: AY
authors: Ting
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D059330:GABAergic Neurons / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics; D051381:Rats; D018079:Receptors, GABA / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism*; D013788:Thalamus / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D015816:Cell Adhesion Molecules, Neuronal; D007136:Immunoglobulins; C486864:MDGA1 protein, rat; C486865:MDGA2 protein, rat; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D019006:Neural Cell Adhesion Molecules; D020543:Proteome; D018079:Receptors, GABA; D011993:Recombinant Fusion Proteins; C098003:neuroligin 2; D018698:Glutamic Acid; D009195:Peroxidase; C042739:antigens, CD200