Nucleocytoplasmic shuttling of dysbindin-1, a schizophrenia-related protein, regulates synapsin I expression

J Biol Chem. 2010 Dec 3;285(49):38630-40. doi: 10.1074/jbc.M110.107912. Epub 2010 Oct 4.

Abstract

Dysbindin-1 is a 50-kDa coiled-coil-containing protein encoded by the gene DTNBP1 (dystrobrevin-binding protein 1), a candidate genetic factor for schizophrenia. Genetic variations in this gene confer a susceptibility to schizophrenia through a decreased expression of dysbindin-1. It was reported that dysbindin-1 regulates the expression of presynaptic proteins and the release of neurotransmitters. However, the precise functions of dysbindin-1 are largely unknown. Here, we show that dysbindin-1 is a novel nucleocytoplasmic shuttling protein and translocated to the nucleus upon treatment with leptomycin B, an inhibitor of exportin-1/CRM1-mediated nuclear export. Dysbindin-1 harbors a functional nuclear export signal necessary for its nuclear export, and the nucleocytoplasmic shuttling of dysbindin-1 affects its regulation of synapsin I expression. In brains of sandy mice, a dysbindin-1-null strain that displays abnormal behaviors related to schizophrenia, the protein and mRNA levels of synapsin I are decreased. These findings demonstrate that the nucleocytoplasmic shuttling of dysbindin-1 regulates synapsin I expression and thus may be involved in the pathogenesis of schizophrenia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Active Transport, Cell Nucleus / genetics
  • Animals
  • Antibiotics, Antineoplastic / pharmacology
  • Brain / metabolism
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism*
  • Cytoplasm / genetics
  • Cytoplasm / metabolism*
  • Dysbindin
  • Dystrophin-Associated Proteins
  • Exportin 1 Protein
  • Fatty Acids, Unsaturated / pharmacology
  • Gene Expression Regulation*
  • HEK293 Cells
  • Humans
  • Karyopherins / antagonists & inhibitors
  • Karyopherins / genetics
  • Karyopherins / metabolism
  • Mice
  • Mice, Mutant Strains
  • Presynaptic Terminals / metabolism
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Receptors, Cytoplasmic and Nuclear / antagonists & inhibitors
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Schizophrenia / genetics
  • Schizophrenia / metabolism*
  • Synapsins / biosynthesis*
  • Synapsins / genetics

Substances

  • Antibiotics, Antineoplastic
  • Carrier Proteins
  • DTNBP1 protein, human
  • Dtnbp1 protein, mouse
  • Dysbindin
  • Dystrophin-Associated Proteins
  • Fatty Acids, Unsaturated
  • Karyopherins
  • RNA, Messenger
  • Receptors, Cytoplasmic and Nuclear
  • Synapsins
  • leptomycin B