Synaptic Glutamate Release in Drosphila

Summary

Principal Investigator: Aaron DiAntonio
Abstract: Glutamate is the primary excitatory neurotransmitter of the vertebrate CNS and the Drosophila neuromuscular junction (NMJ). The vesicular glutamate transporter (VGLUT) is responsible for filling synaptic vesicles with transmitter at glutamatergic synapses. The glutamate content of a synaptic vesicle is a fundamental parameter controlling the strength of synaptic transmission in the healthy brain, while the misregulated release of vesicular glutamate may contribute to the pathophysiology of such diseases as stroke, ALS, and epilepsy. This proposal will test the hypothesis that the expression, trafficking, and activity of the Drosophila homolog of VGLUT (D VGLUT) regulates the function, plasticity, and development of a glutamatergic synapse by controlling the glutamate content of synaptic vesicles. Our studies will combine genetic, cell biological, and electrophysiological methods to test the function of this important protein. The Drosophila homolog of the vesicular glutamate transporter (DVGLUT) has been identified and mutants have been generated that allow for the manipulation of its expression at the synapse. Biochemical, electrophysiological, and electron microscopic techniques will be employed to investigate the physiological role of DVGLUT in the filling of synaptic vesicles with glutamate (Aim 1). Neurotransmitter not only mediates synaptic transmission, but can also regulate the development of synapses. DVGLUT mutants will be used to manipulate the levels of glutamate in synaptic vesicles and the consequences for synapse formation, glutamate receptor localization, and synaptic maturation will be investigated (Aim 2). Finally, the mechanisms regulating the membrane trafficking of DVGLUT will be determined in order to define the role of DVGLUT trafficking in the regulation of glutamatergic transmission (Aim 3). The results of these experiments will provide novel and fundamental information on the mechanisms by which VGLUT contributes to the development and function of glutamatergic synapses.
Funding Period: 2005-04-01 - 2010-03-31
more information: NIH RePORT

Top Publications

  1. ncbi Synaptic development: insights from Drosophila
    Catherine A Collins
    Department of Molecular Biology and Pharmacology, Campus Box 8103, 660 South Euclid, Washington University School of Medicine, St Louis, MO 63110, USA
    Curr Opin Neurobiol 17:35-42. 2007
  2. ncbi A screen for neurotransmitter transporters expressed in the visual system of Drosophila melanogaster identifies three novel genes
    Rafael Romero-Calderon
    Interdepartmental Ph D Program in Neuroscience, University of California, Los Angeles, California 90095 1761, USA
    Dev Neurobiol 67:550-69. 2007
  3. ncbi Visualizing glutamatergic cell bodies and synapses in Drosophila larval and adult CNS
    Richard W Daniels
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St Louis, Missouri 63110, USA
    J Comp Neurol 508:131-52. 2008
  4. pmc Trafficking of vesicular neurotransmitter transporters
    Hao Fei
    Departments of Psychiatry and Neurobiology, Gonda Goldschmied Neuroscience and Genetics Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 1761, USA
    Traffic 9:1425-36. 2008
  5. pmc Drosophila vesicular monoamine transporter mutants can adapt to reduced or eliminated vesicular stores of dopamine and serotonin
    Anne F Simon
    Department of Developmental Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA
    Genetics 181:525-41. 2009
  6. pmc A tyrosine-based motif localizes a Drosophila vesicular transporter to synaptic vesicles in vivo
    Anna Grygoruk
    Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Hatos Center for Neuropharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California 90095 1761, USA
    J Biol Chem 285:6867-78. 2010
  7. pmc Increased vesicular glutamate transporter expression causes excitotoxic neurodegeneration
    Richard W Daniels
    Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
    Neurobiol Dis 41:415-20. 2011

Detail Information

Publications7

  1. ncbi Synaptic development: insights from Drosophila
    Catherine A Collins
    Department of Molecular Biology and Pharmacology, Campus Box 8103, 660 South Euclid, Washington University School of Medicine, St Louis, MO 63110, USA
    Curr Opin Neurobiol 17:35-42. 2007
    ....
  2. ncbi A screen for neurotransmitter transporters expressed in the visual system of Drosophila melanogaster identifies three novel genes
    Rafael Romero-Calderon
    Interdepartmental Ph D Program in Neuroscience, University of California, Los Angeles, California 90095 1761, USA
    Dev Neurobiol 67:550-69. 2007
    ..These data suggest an unforeseen role for the "nutrient amino acid transporter" subfamily in the nervous system, and suggest new models to study transport function using the fly eye...
  3. ncbi Visualizing glutamatergic cell bodies and synapses in Drosophila larval and adult CNS
    Richard W Daniels
    Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St Louis, Missouri 63110, USA
    J Comp Neurol 508:131-52. 2008
    ..This description of the glutamatergic system in Drosophila highlights the prevalence of glutamatergic neurons in the CNS and presents tools for future study and manipulation of glutamatergic transmission...
  4. pmc Trafficking of vesicular neurotransmitter transporters
    Hao Fei
    Departments of Psychiatry and Neurobiology, Gonda Goldschmied Neuroscience and Genetics Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095 1761, USA
    Traffic 9:1425-36. 2008
    ..In addition, VGLUT1 uses alternative endocytic pathways for recycling back to SVs following exocytosis. Regulation of these sorting events has the potential to influence synaptic transmission and behavior...
  5. pmc Drosophila vesicular monoamine transporter mutants can adapt to reduced or eliminated vesicular stores of dopamine and serotonin
    Anne F Simon
    Department of Developmental Biology, Washington University School of Medicine, St Louis, Missouri 63110, USA
    Genetics 181:525-41. 2009
    ..dVMAT mutants define potentially adaptive responses to reduced or eliminated aminergic signaling and will be useful to identify the underlying molecular mechanisms...
  6. pmc A tyrosine-based motif localizes a Drosophila vesicular transporter to synaptic vesicles in vivo
    Anna Grygoruk
    Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, Hatos Center for Neuropharmacology, David Geffen School of Medicine, UCLA, Los Angeles, California 90095 1761, USA
    J Biol Chem 285:6867-78. 2010
    ..Our data show for the first time that mutation of a specific trafficking motif can disrupt localization to SVs in vivo and suggest possible differences in the sorting of VMATs versus VGLUTs to SVs at the synapse...
  7. pmc Increased vesicular glutamate transporter expression causes excitotoxic neurodegeneration
    Richard W Daniels
    Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
    Neurobiol Dis 41:415-20. 2011
    ..Thus overexpression of DVGLUT is sufficient to generate excitotoxic neuropathological phenotypes and therefore reducing VGLUT levels after nervous system injury or stress may mitigate further damage...