Glutamate is the main excitatory neurotransmitter in the mammalian central nervous system and is removed from the synaptic cleft by sodium-dependent glutamate transporters. To date, five distinct glutamate transporters have been cloned from animal and human tissue: GLAST (EAAT1), GLT-1 (EAAT2), EAAC1 (EAAT3), EAAT4, and EAAT5 (refs 1,2,3,4,5). GLAST and GLT-1 are localized primarily in astrocytes6,7, whereas EAAC1 (refs 8, 9), EAAT4 (refs 9,10,11) and EAAT5 (ref. 5) are neuronal. Studies of EAAT4 and EAAC1 indicate an extrasynaptic localization on perisynaptic membranes that are near release sites8,9,10. This localization facilitates rapid glutamate binding, and may have a role in shaping the amplitude of postsynaptic responses in densely packed cerebellar terminals12,13,14,15. We have used a yeast two-hybrid screen to identify interacting proteins that may be involved in regulating EAAT4—the glutamate transporter expressed predominately in the cerebellum—or in targeting and/or anchoring or clustering the transporter to the target site. Here we report the identification and characterization of two proteins, GTRAP41 and GTRAP48 (for glutamate transporter EAAT4 associated protein) that specifically interact with the intracellular carboxy-terminal domain of EAAT4 and modulate its glutamate transport activity.
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Storck, T., Schulte, S., Hofmann, K. & Stoffel, W. Structure, expression, and functional analysis of a Na+-dependent glutamate/aspartate transporter from rat brain. Proc. Natl Acad. Sci. USA 89, 10955– 10959 (1992).
Kanai, Y. & Hediger, M. A. Primary structure and functional characterization of a high-affinity glutamate transporter. Nature 360, 467– 471 (1992).
Pines, G. et al. Cloning and expression of a rat brain L-glutamate transporter. Nature 360, 464–467 (1992); erratum ibid. 360, 768 (1992).
Fairman, W. A., Vandenberg, R. J., Arriza, J. L., Kavanaugh, M. P. & Amara, S. G. An excitatory amino-acid transporter with properties of a ligand-gated chloride channel. Nature 375, 599– 603 (1995).
Arriza, J. L., Eliasof, S., Kavanaugh, M. P. & Amara, S. G. Excitatory amino acid transporter 5, a retinal glutamate transporter coupled to a chloride conductance. Proc. Natl Acad. Sci. USA 94, 4155– 4160 (1997).
Rothstein, J. D. et al. Localization of neuronal and glial glutamate transporters. Neuron 13, 713– 725 (1994).
Danbolt, N. C., Storm-Mathisen, J. & Kanner, B. I. An [Na+ + K+]coupled l-glutamate transporter purified from rat brain is located in glial cell processes. Neuroscience 51, 295– 310 (1992).
He, Y., Janssen, W. G., Rothstein, J. D. & Morrison, J. H. Differential synaptic localization of the glutamate transporter EAAC1 and glutamate receptor subunit GluR2 in the rat hippocampus. J. Comp. Neurol. 418, 255– 269 (2000).
Furuta, A., Martin, L. J., Lin, C. L., Dykes-Hoberg, M. & Rothstein, J. D. Cellular and synaptic localization of the neuronal glutamate transporters excitatory amino acid transporter 3 and 4. Neuroscience 81, 1031– 1042 (1997).
Dehnes, Y. et al. The glutamate transporter EAAT4 in rat cerebellar Purkinje cells: a glutamate-gated chloride channel concentrated near the synapse in parts of the dendritic membrane facing astroglia. J. Neurosci. 18, 3606– 3619 (1998).
Nagao, S., Kwak, S. & Kanazawa, I. EAAT4, a glutamate transporter with properties of a chloride channel, is predominantly localized in Purkinje cell dendrites, and forms parasagittal compartments in rat cerebellum. Neuroscience 78, 929– 933 (1997).
Tong, G. & Jahr, C. E. Block of glutamate transporters potentiates postsynaptic excitation. Neuron 13, 1195– 1203 (1994).
Diamond, J. S. & Jahr, C. E. Transporters buffer synaptically released glutamate on a submillisecond time scale. J. Neurosci. 17, 4672– 4687 (1997).
Overstreet, L. S., Kinney, G. A., Liu, Y. B., Billups, D. & Slater, N. T. Glutamate transporters contribute to the time course of synaptic transmission in cerebellar granule cells. J. Neurosci. 19, 9663– 9673 (1999).
Barbour, B., Keller, B. U., Llano, I. & Marty, A. Prolonged presence of glutamate during excitatory synaptic transmission to cerebellar Purkinje cells. Neuron 12, 1331– 1343 (1994).
Hart, M. J. et al. Identification of a novel guanine nucleotide exchange factor for the Rho GTPase. J. Biol. Chem. 271, 25452– 25458 (1996).
Fukuhara, S., Murga, C., Zohar, M., Igishi, T. & Gutkind, J. S. A novel PDZ domain containing guanine nucleotide exchange factor links heterotrimeric G proteins to Rho. J. Biol. Chem. 274, 5868– 5879 (1999).
Hart, M. J. et al. Direct stimulation of the guanine nucleotide exchange activity of p115 RhoGEF by Gα13. Science 280, 2112– 2114 (1998).
Hall, A. Rho GTPases and the actin cytoskeleton. Science 279, 509– 514 (1998).
Lin, X., Antalffy, B., Kang, D., Orr, H. T. & Zoghbi, H. Y. Polyglutamine expansion down-regulates specific neuronal genes before pathologic changes in SCA1. Nature Neurosci. 3, 157– 163 (2000).
Blackstone, C. D. et al. Biochemical characterization and localization of a non-N-methyl-d- aspartate glutamate receptor in rat brain. J. Neurochem. 58, 1118– 1126 (1992).
Davis, K.E. et al. Multiple signaling pathways regulate cell surface expression and activity of the excitatory amino acid carrier 1 subtype of Glu transporter in C6 glioma. J. Neurosci. 18, 2475-2485 (1998).
Geller, A.I., Keyomarsi, K., Bryan, J. & Pardee, A.B. An efficient deletion mutant packaging system for defective herpes simplex virus vectors: potential applications to human gene therapy and neuronal physiology. Proc. Natl Acad. Sci. USA 87, 8950– 8954 (1990).
Stavropoulos, T. A. & Strathdee, C. A. An enhanced packaging system for helper-dependent herpes simplex virus vectors. J. Virol. 72, 7137– 7143 (1998).
Bowers, W. J., Howard, D. F. & Federoff, H. J. Discordance between expression and genome transfer titering of HSV amplicon vectors: recommendation for standardized enumeration. Mol. Ther. 1, 294– 299 (2000).
Duan, S., Anderson, C. M., Stein, B. A. & Swanson, R. A. Glutamate induces rapid upregulation of astrocyte glutamate transport and cell-surface expression of GLAST. J. Neurosci. 19, 10193– 10200 (1999).
We thank N. J. Maragakis, M. Watanabe, A. Sawa, R. Ganel, J. Llado and R. Law for discussions, advice and help. We thank R. Huganir for the pRK5 vector and D. Howard for technical assistance. This work was supported by the NIH.
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Jackson, M., Song, W., Liu, MY. et al. Modulation of the neuronal glutamate transporter EAAT4 by two interacting proteins. Nature 410, 89–93 (2001). https://doi.org/10.1038/35065091
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