title: Detergent-dependent separation of postsynaptic density, membrane rafts and other subsynaptic structures from the synaptic plasma membrane of rat forebrain.
abstract: We systematically investigated the purification process of post-synaptic density (PSD) and post-synaptic membrane rafts (PSRs) from the rat forebrain synaptic plasma membranes by examining the components and the structures of the materials obtained after the treatment of synaptic plasma membranes with TX-100, n-octyl β-d-glucoside (OG) or 3-([3-cholamidopropyl]dimethylammonio)-2-hydroxy-1-propanesulfonate (CHAPSO). These three detergents exhibited distinct separation profiles for the synaptic subdomains. Type I and type II PSD proteins displayed mutually exclusive distribution. After TX-100 treatment, type I PSD was recovered in two fractions: a pellet and an insoluble fraction 8, which contained partially broken PSD-PSR complexes. Conventional PSD was suggested to be a mixture of these two PSD pools and did not contain type II PSD. An association of type I PSD with PSRs was identified in the TX-100 treatment, and those with type II PSD in the OG and CHAPSO treatments. An association of GABA receptors with gephyrin was easily dissociated. OG at a high concentration solubilized the type I PSD proteins. CHAPSO treatment resulted in a variety of distinct fractions, which contained certain novel structures. Two different pools of GluA, either PSD or possibly raft-associated, were identified in the OG and CHAPSO treatments. These results are useful in advancing our understanding of the structural organization of synapses at the molecular level. We systematically investigated the purification process of post-synaptic density (PSD) and synaptic membrane rafts by examining the structures obtained after treatment of the SPMs with TX-100, n-octyl β-d-glucoside or CHAPSO. Differential distribution of type I and type II PSD, synaptic membrane rafts, and other novel subdomains in the SPM give clues to understand the structural organization of synapses at the molecular level.
authors.affiliation: Department of Neuroplasticity, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, Shinshu University Academic Assembly, Matsumoto, Japan.
authors.forename: LiYing
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sakagami
authors.affiliation: Department of Neuroplasticity, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, Shinshu University Academic Assembly, Matsumoto, Japan.|Department of Biological Sciences for Intractable Neurological Diseases, Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Matsumoto, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D003902:Detergents / Q000494:pharmacology*; D008297:Male; D021962:Membrane Microdomains / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D008969:Molecular Sequence Data; D057907:Post-Synaptic Density / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D016548:Prosencephalon / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D051381:Rats; D017208:Rats, Wistar; D013570:Synaptic Membranes / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*
chemical_list: D003902:Detergents
keywords: PSD; detergent-resistant membranes; membrane rafts; post-synaptic density; type I synapse; type II synapse