title: The trafficking proteins Vacuolar Protein Sorting 35 and Neurobeachin interact with the glycine receptor β-subunit.
abstract: Inhibitory glycine receptors (GlyRs) are densely packed in the postsynaptic membrane due to a high-affinity interaction of their β-subunits with the scaffolding protein gephyrin. Here, we used an affinity-based proteomic approach to identify the trafficking proteins Vacuolar Protein Sorting 35 (Vps35) and Neurobeachin (Nbea) as novel GlyR β-subunit (GlyRβ) interacting proteins in rat brain. Recombinant Vps35 and a central fragment of Nbea bound to the large intracellular loop of GlyRβ in glutathione-S-transferase pull-downs; in addition, Vps35 displayed binding to gephyrin. Immunocytochemical staining of spinal cord sections revealed Nbea immunoreactivity apposed to and colocalizing with marker proteins of inhibitory synapses. Our data are consistent with roles of Vps35 and Nbea in the retrieval and post-Golgi trafficking of synaptic GlyRs and possibly other neurotransmitter receptors.
authors.affiliation: Department of Neurochemistry, Max-Planck-Institute for Brain Research, D-60528 Frankfurt/Main, Germany.
authors.forename: Isabel
authors.initials: I
authors.lastname: del Pino
authors.forename: Ingo
authors.initials: I
authors.lastname: Paarmann
authors.forename: Michael
authors.initials: M
authors.lastname: Karas
authors.forename: Manfred W
authors.initials: MW
authors.lastname: Kilimann
authors.forename: Heinrich
authors.initials: H
authors.lastname: Betz
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D051381:Rats; D018009:Receptors, Glycine / Q000235:genetics / Q000378:metabolism*; D013116:Spinal Cord; D013569:Synapses / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C491948:Glrb protein, rat; D008565:Membrane Proteins; C562318:Nbea protein, rat; D018009:Receptors, Glycine; D033921:Vesicular Transport Proteins; C073441:gephyrin; C562317:vacuolar protein sorting 35, rat