Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Identification and characterization of the vesicular GABA transporter

Abstract

Synaptic transmission involves the regulated exocytosis of vesicles filled with neurotransmitter. Classical transmitters are synthesized in the cytoplasm, and so must be transported into synaptic vesicles. Although the vesicular transporters for monoamines and acetylcholine have been identified, the proteins responsible for packaging the primary inhibitory and excitatory transmitters, γ-aminobutyric acid (GABA) and glutamate remain unknown1,2. Studies in the nematode Caenorhabditis elegans have implicated the gene unc-47 in the release of GABA3. Here we show that the sequence of unc-47 predicts a protein with ten transmembrane domains, that the gene is expressed by GABA neurons, and that the protein colocalizes with synaptic vesicles. Further, a rat homologue of unc-47 is expressed by central GABA neurons and confers vesicular GABA transport in transfected cells with kinetics and substrate specificity similar to those previously reported for synaptic vesicles from the brain. Comparison of this vesicular GABA transporter (VGAT) with a vesicular transporter for monoamines shows that there are differences in the bioenergetic dependence of transport, and these presumably account for the differences in structure. Thus VGAT is the first of a new family of neurotransmitter transporters.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Sequence and structure of the vesicular GABA transporter.
Figure 2: Sequence and structure of the vesicular GABA transporter.
Figure 3: The unc-47 gene is transcribed in GABAergic neurons, and the protein colocalizes with synaptic vesicles.
Figure 4: Brain-specific expression of the rat unc-47 homologue.
Figure 5: In situ hybridization shows expression of the rat unc-47 homologue in GABAergic cell populations.
Figure 6: In situ hybridization shows expression of the rat unc-47 homologue in GABAergic cell populations.
Figure 7: The rat unc-47 homologue encodes vesicular GABA transport.

Similar content being viewed by others

References

  1. Schuldiner, S., Shirvan, A. & Linial, M. Vesicular neurotransmitter transporters: from bacteria to humans. Physiol. Rev. 75, 369–392 (1995).

    Article  CAS  Google Scholar 

  2. Liu, Y. & Edwards, R. H. The role of vesicular transport proteins in synaptic transmission and neural degeneration. Annu. Rev. Neurosci. 20, 125–156 (1997).

    Article  CAS  Google Scholar 

  3. McIntire, S., Jorgensen, E. & Horvitz, H. R. Genes required for GABA function in Caenorhabditis elegans. Nature 364, 337–341 (1993).

    Article  ADS  CAS  Google Scholar 

  4. Liu, Y. et al. AcDNA that supresses MPP+ toxicity encodes a vesicular amine transporter. Cell 70, 539–551 (1992).

    Article  CAS  Google Scholar 

  5. Erickson, J. D., Eiden, L. E. & Hoffman, B. J. Expression cloning of a reserpine-sensitive vesicular monoamine transporter. Proc. Natl Acad. Sci. USA 89, 10993–10997 (1992).

    Article  ADS  CAS  Google Scholar 

  6. Alfonso, A., Grundahl, K., Duerr, J. S., Han, H.-P. & Rand, J. B. The Caenorhabditis elegans unc-17 gene: a putative vesicular acetylcholine transporter. Science 261, 617–619 (1993).

    Article  ADS  CAS  Google Scholar 

  7. McIntire, S., Jorgensen, E., Kaplan, J. & Horvitz, H. R. The GABAergic nervous system of Caenorhabditis elegans. Nature 364, 334–337 (1993).

    Article  ADS  CAS  Google Scholar 

  8. Wilson, R. et al. 2.2 Mb of contiguous nucleotide sequence from chromosome III of C. elegans. Nature 368, 32–38 (1994).

    Article  ADS  CAS  Google Scholar 

  9. Brenner, S. The genetics of Caenorhabditis elegans. Genetics 77, 71–94 (1974).

    CAS  PubMed  PubMed Central  Google Scholar 

  10. Chalfie, M., Tu, Y., Euskirchen, G., Ward, W. W. & Prasher, D. C. Green fluorescent protein as a marker for gene expression. Science 263, 802–805 (1994).

    Article  ADS  CAS  Google Scholar 

  11. Clark, S. G., Lu, X. & Horvitz, H. R. The Caenorhabiditis elegans locus lin-15, a negative regulator of a tyrosine kinase signaling pathway, encodes two different proteins. Genetics 137, 987–997 (1994).

    CAS  PubMed  PubMed Central  Google Scholar 

  12. Ferguson, E. L. & Horvitz, H. R. Identification and characterization of 22 genes that affect the vulval cell lineages of the nematode Caenorhabidits elegans. Genetics 110, 17–72 (1985).

    CAS  PubMed  PubMed Central  Google Scholar 

  13. Jorgensen, E. M. et al. Defective recycling of synaptic vesicles in synaptotagmin mutants of Caenorhabditis elegans. Nature 378, 196–199 (1995).

    Article  ADS  CAS  Google Scholar 

  14. Nonet, M. L., Grundahl, K., Meyer, B. J. & Rand, J. B. Synaptic function is impaired but not eliminated in C. elegans mutants lacking synaptotagmin. Cell 73, 1291–1306 (1993).

    Article  CAS  Google Scholar 

  15. Nonet, M. L. et al. Functional synapses are partially depleted of vesicles in C. elegans rab-3 mutants. J. Neurosci.(in the press).

  16. Hall, D. H. & Hedgecock, E. M. Kinesin-related gene unc-104 is required for axonal transport of synaptic vesicles in C. elegans. Cell 65, 837–847 (1991).

    Article  CAS  Google Scholar 

  17. Thomas-Reetz, A. et al. γ-aminobutyric acid transporter driven by a proton pump is present in synaptic-like microvesicles of pancreatic B cells. Proc. Natl Acad. Sci. USA 90, 5317–5321 (1993).

    Article  ADS  CAS  Google Scholar 

  18. Liu, Y. et al. Preferential localization of a vesicular monoamine transporter to dense core vesicle in PC12 cells. J. Cell Biol. 127, 1419–1433 (1994).

    Article  CAS  Google Scholar 

  19. Varoqui, H. & Erickson, J. D. Active transport of acetylcholine by the human vesicular acetylcholine transporter. J. Biol. Chem. 271, 27229–27232 (1996).

    Article  CAS  Google Scholar 

  20. Fykse, E. M. & Fonnum, F. Uptake of γ-aminobutyric acid by a synaptic vesicle fraction isolated from rat brain. J. Neurochem. 50, 1237–1242 (1988).

    Article  CAS  Google Scholar 

  21. Hell, J. W., Maycox, P. R., Stadler, H. & Jahn, R. Uptake of GABA by rat brain synaptic vesicles isolated by a new procedure. EMBO J. 7, 3023–3029 (1988).

    Article  CAS  Google Scholar 

  22. Kish, P. E., Fischer-Bovenkerk, C. & Ueda, T. Active transport of γ-aminobutyric acid and glycine into synaptic vesicles. Proc. Natl Acad. Sci. USA 86, 3877–3881 (1989).

    Article  ADS  CAS  Google Scholar 

  23. Burger, P. M. et al. GABA and glycine in synaptic vesicles: storage and transport characteristics. Neuron 7, 287–293 (1991).

    Article  CAS  Google Scholar 

  24. Naito, S. & Ueda, T. Adenosine triphosphate-dependent uptake of glutamate into protein I-associated synaptic vesicles. J. Biol. Chem. 258, 696–699 (1983).

    CAS  PubMed  Google Scholar 

  25. Maycox, P. R., Deckwerth, T., Hell, J. W. & John, R. Glutamate uptake by brain synaptic vesicles. Energy dependence of transport and functional reconstitution in proteoliposomes. J. Biol. Chem. 263, 15423–15428 (1988).

    CAS  PubMed  Google Scholar 

  26. Carlson, M. D., Kish, P. E. & Ueda, T. Glutamate uptake into synaptic vesicles: competitive inhibition by bromocriptine. J. Neurochem. 53, 1889–1894 (1989).

    Article  CAS  Google Scholar 

  27. Christensen, H., Fykse, E. M. & Fonnum, F. Inhibition of γ-aminobutyrate and glycine uptake into synaptic vesicles. Eur. J. Pharmacol. 207, 73–79 (1991).

    Article  CAS  Google Scholar 

  28. Fischer, W. N., Kwart, M., Hummel, S. & Frommer, W. B. Substrate specificity and expression of profile of amino acid transporters (AAPs) in Arabidopsis. J. Biol. Chem. 270, 16315–16320 (1995).

    Article  CAS  Google Scholar 

  29. Sassoon, D. & Rosenthal, N. in Guide to Techniques in Mouse Development(eds Wassarman, P. M. & DePamphilis, M. L.) 384–404 (Academic, San Diego, (1993)).

    Book  Google Scholar 

  30. Grote, E., Hao, J. C., Bennett, M. K. & Kelly, R. B. Atargeting signal in VAMP regulating transport ot synaptic vesicles. Cell 81, 581–589 (1995).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank B. Westlund for unpublished unc-47 map data; E. King for help with the confocal microscope; H. Rausch and K. Knobel for integrating the unc-47::GFP transcriptional fusion construct; Y. Jin for the n2476 allele; D. P. Morse and B. Bamber for the gift of RNA and cDNA; R. Barstead and P. Okkema for the C. elegans cDNA libraries; J. Boulter and D. Julius for the mammalian cDNA libraries; D. Rice and D. Eisenberg for the analysis of hydrophobic moment; A. Tobin and S. Baekkeskov for the GAD-67 cDNA; Y. Liu and P. Tan for assistance in the isolation of PC12 cell clones and the preparation of membranes; J. Hell and P. Finn for suggestions about the measurement of transport activity; S. Craven and D. Bredt for assistance with the primary hippocampal cultures; and M. Horner, E.Kofoid, C. Bargmann and members of the Edwards and Jorgensen laboratories for discussions. This work was supported by the Gallo Center (S.L.M.), the Giannini Foundation (R.J.R.), an NIH Developmental Biology training grant (K.S.), the Klingenstein Foundation (E.M.J.), NINDS (S.L.M., R.H.E., E.M.J.) and NIMH (R.H.E.).

Author information

Authors and Affiliations

Authors

Corresponding authors

Correspondence to Robert H. Edwards or Erik M. Jorgensen.

Rights and permissions

Reprints and permissions

About this article

Cite this article

McIntire, S., Reimer, R., Schuske, K. et al. Identification and characterization of the vesicular GABA transporter. Nature 389, 870–876 (1997). https://doi.org/10.1038/39908

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/39908

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing