title: Dysbindin-associated proteome in the p2 synaptosome fraction of mouse brain.
abstract: The gene DTNBP1 encodes the protein dysbindin and is among the most promising and highly investigated schizophrenia-risk genes. Accumulating evidence suggests that dysbindin plays an important role in the regulation of neuroplasticity. Dysbindin was reported to be a stable component of BLOC-1 complex in the cytosol. However, little is known about the endogenous dysbindin-containing complex in the brain synaptosome. In this study, we investigated the associated proteome of dysbindin in the P2 synaptosome fraction of mouse brain. Our data suggest that dysbindin has three isoforms associating with different complexes in the P2 fraction of mouse brain. To facilitate immunopurification, BAC transgenic mice expressing a tagged dysbindin were generated, and 47 putative dysbindin-associated proteins, including all components of BLOC-1, were identified by mass spectrometry in the dysbindin-containing complex purified from P2. The interactions of several selected candidates, including WDR11, FAM91A1, snapin, muted, pallidin, and two proteasome subunits, PSMD9 and PSMA4, were verified by coimmunoprecipitation. The specific proteasomal activity is significantly reduced in the P2 fraction of the brains of the dysbindin-null mutant (sandy) mice. Our data suggest that dysbindin is functionally interrelated to the ubiquitin-proteasome system and offer a molecular repertoire for future study of dysbindin functional networks in brain.
authors.affiliation: National Institute of Mental Health , Bethesda, Maryland 20892, United States.
authors.forename: Meng-Hsuan J
authors.initials: MH
authors.lastname: Han
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Hu
authors.forename: Cai Yun
authors.initials: CY
authors.lastname: Chen
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Marjan
authors.initials: M
authors.lastname: Gucek
authors.forename: Zheng
authors.initials: Z
authors.lastname: Li
authors.forename: Sanford P
authors.initials: SP
authors.lastname: Markey
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism; D000074765:Dysbindin; D049029:Dystrophin-Associated Proteins / Q000378:metabolism*; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins / Q000378:metabolism; D013058:Mass Spectrometry; D051379:Mice; D008822:Mice, Transgenic; D046912:Multiprotein Complexes / Q000302:isolation & purification / Q000378:metabolism*; D009473:Neuronal Plasticity / Q000502:physiology*; D020033:Protein Isoforms / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D012559:Schizophrenia / Q000235:genetics*; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: C513476:Bloc1s6 protein, mouse; D002352:Carrier Proteins; C498992:Dtnbp1 protein, mouse; D000074765:Dysbindin; D049029:Dystrophin-Associated Proteins; D047908:Intracellular Signaling Peptides and Proteins; D037102:Lectins; D046912:Multiprotein Complexes; D020033:Protein Isoforms; D020543:Proteome
keywords: BAC transgenesis; Dysbindin; mass spectrometry; proteasome; protein complex; protein−protein interaction; schizophrenia; synaptosome