Synaptic functions and synaptic plasticity are crucial for information transfer and storage in the brain, but the structure of synapses in the mammalian central nervous system (CNS) is poorly understood, especially at the molecular level. The broad long term objective of this proposal is to understand the molecular basis of postsynaptic organization and diversity in the CNS, with particular reference to protein-protein interactions at the synaptic membrane.
The specific aim i s to define and characterize the molecules which mediate the clustering and anchoring of two different classes of neurotransmitter receptor (NMDA receptors and GABAA receptors) at excitatory and inhibitory postsynaptic sites, respectively. The experimental approach is to identify intracellular proteins which bind specifically to NMDA and GABAA receptors, by using the major intracellular domain of subunits of these receptors as baits in a yeast two-hybrid screen of a brain cDNA library. In Preliminary studies, a known actin binding protein (a-actinin) and a novel extended coiled-coil protein (termed NIP-1), have been identified as molecules that interact directly with separate domains with the cytoplasmic C-terminal tail of the NMDA receptor subunit NR1. These results demonstrate the feasibility of the two-hybrid approach to detect potential interaction between integral synaptic membrane proteins and components of the postsynaptic cortical cytoskeleton. The authenticity of the protein interactions identified by the two-hybrid system will be confirmed in vitro by binding of recombinant proteins, and in vivo (rat brain) by immunohistochemical co-localization and immunoprecipitation. Protein domains mediating the interaction will be will be defined by deletional mutagenesis, with the hope of identifying novel sequence motifs or modules for protein-protein interactions at the cell membrane. The functional significance of receptor association with its binding protein will be investigated by co-transfection experiments in cultured cells. Developmental and cellular expression patterns of the proteins interaction with NMDA receptor and GABAA receptors will be characterized in rat brain. Determining the molecular organization of receptors in postsynaptic membranes will further our understanding of the mechanisms of synaptogenesis and synaptic structural plasticity, and hence of learning and memory, and developmental and aging processes in the brain. From a clinical point of view, abnormalities in the organization of the postsynaptic membrane and cytoskeleton in the CNS could results in neurological disease, just as defects in the muscle membrane cytoskeletal protein dystrophin can cause muscular dystrophy. In the context, it is of interest that our preliminary studies have identified a relative of dystrophin (a-actinin) as a putative anchoring protein for the NMDA receptor.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
1R01NS035050-01
Application #
2274388
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1996-05-01
Project End
2001-04-30
Budget Start
1996-05-01
Budget End
1997-04-30
Support Year
1
Fiscal Year
1996
Total Cost
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02199
Berns, Dominic S; DeNardo, Laura A; Pederick, Daniel T et al. (2018) Teneurin-3 controls topographic circuit assembly in the hippocampus. Nature 554:328-333
Lee, Sang Hyoung; Simonetta, Alyson; Sheng, Morgan (2004) Subunit rules governing the sorting of internalized AMPA receptors in hippocampal neurons. Neuron 43:221-36
Ahmadian, Gholamreza; Ju, William; Liu, Lidong et al. (2004) Tyrosine phosphorylation of GluR2 is required for insulin-stimulated AMPA receptor endocytosis and LTD. EMBO J 23:1040-50
Sheng, Morgan; Hyoung Lee, Sang (2003) AMPA receptor trafficking and synaptic plasticity: major unanswered questions. Neurosci Res 46:127-34
Lee, Sang Hyoung; Liu, Lidong; Wang, Yu Tian et al. (2002) Clathrin adaptor AP2 and NSF interact with overlapping sites of GluR2 and play distinct roles in AMPA receptor trafficking and hippocampal LTD. Neuron 36:661-74
Wyszynski, Michael; Kim, Eunjoon; Dunah, Anthone W et al. (2002) Interaction between GRIP and liprin-alpha/SYD2 is required for AMPA receptor targeting. Neuron 34:39-52
Pak, D T; Yang, S; Rudolph-Correia, S et al. (2001) Regulation of dendritic spine morphology by SPAR, a PSD-95-associated RapGAP. Neuron 31:289-303
Passafaro, M; Piech, V; Sheng, M (2001) Subunit-specific temporal and spatial patterns of AMPA receptor exocytosis in hippocampal neurons. Nat Neurosci 4:917-26
Lee, S H; Valtschanoff, J G; Kharazia, V N et al. (2001) Biochemical and morphological characterization of an intracellular membrane compartment containing AMPA receptors. Neuropharmacology 41:680-92
Burette, A; Khatri, L; Wyszynski, M et al. (2001) Differential cellular and subcellular localization of ampa receptor-binding protein and glutamate receptor-interacting protein. J Neurosci 21:495-503

Showing the most recent 10 out of 29 publications