Eunjoon Kim

The molecular mechanisms underlying the organization of ion channels and signaling molecules at the synaptic junction are largely unknown. Recently, members of the PSD-95/SAP90 family of synaptic MAGUK (membrane-associated guanylate kinase) proteins have been shown to interact, via their NH2-terminal PDZ domains, with certain ion channels (NMDA receptors and K+ channels), thereby promoting the clustering of these proteins. Although the function of the NH2-terminal PDZ domains is relatively well

Shank1, Shank2, and Shank3 constitute a family of proteins that may function as molecular scaffolds in the postsynaptic density (PSD). Shank directly interacts with GKAP and Homer, thus potentially bridging the N-methyl-D-aspartate receptor-PSD-95-GKAP complex and the mGluR-Homer complex in synapses (Naisbitt, S., Kim, E., Tu, J. C. , Xiao, B., Sala, S., Valtschanoff, J., Weinberg, R. J., Worley, P. F., and Sheng, M. (1999) Neuron 23, 569-582; Tu, J. C., Xiao, B., Naisbitt, S., Yuan, J. P., Petr

Liprin-alpha/SYD-2 is a multimodular scaffolding protein important for presynaptic differentiation and postsynaptic targeting of alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionic acid glutamate receptors. However, the molecular mechanisms underlying these functions remain largely unknown. Here we report that liprin-alpha interacts with the neuron-specific kinesin motor KIF1A. KIF1A colocalizes with liprin-alpha in various subcellular regions of neurons. KIF1A coaccumulates with liprin-alpha i

Liprin-alpha/SYD-2 is a family of multidomain proteins with four known isoforms. One of the reported functions of liprin-alpha is to regulate the development of presynaptic active zones, but the underlying mechanism is poorly understood. Here we report that liprin-alpha directly interacts with the ERC (ELKS-Rab6-interacting protein-CAST) family of proteins, members of which are known to bind RIMs, the active zone proteins that regulate neurotransmitter release. In vitro results indicate that ERC

The Shank/ProSAP family of multidomain proteins is known to play an important role in organizing synaptic multiprotein complexes. Here we report a novel interaction between Shank and beta PIX, a guanine nucleotide exchange factor for the Rac1 and Cdc42 small GTPases. This interaction is mediated by the PDZ domain of Shank and the C-terminal leucine zipper domain and the PDZ domain-binding motif at the extreme C terminus of beta PIX. Shank colocalizes with beta PIX at excitatory synaptic sites in

Synaptic cell adhesion molecules regulate various steps of synapse formation. The trans-synaptic adhesion between postsynaptic NGL-3 (for netrin-G ligand-3) and presynaptic LAR (for leukocyte antigen-related) regulates excitatory synapse formation in a bidirectional manner. However, little is known about the molecular details of the NGL-3-LAR adhesion and whether two additional LAR family proteins, protein-tyrosine phosphatase delta (PTPdelta), and PTPsigma, also interact with NGL-3 and are invo