Letter | Published:

Functional architecture of an intracellular membrane t-SNARE

Nature volume 407, pages 198202 (14 September 2000) | Download Citation



Lipid bilayer fusion is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs)1,2. The assembled v-SNARE/t-SNARE complex consists of a bundle of four helices, of which one is supplied by the v-SNARE and the other three by the t-SNARE3. For t-SNAREs on the plasma membrane, the protein syntaxin4 supplies one helix and a SNAP-25 protein5 contributes the other two. Although there are numerous homologues of syntaxin on intracellular membranes6, there are only two SNAP-25-related proteins in yeast, Sec9 and Spo20, both of which are localized to the plasma membrane and function in secretion7 and sporulation8, respectively. What replaces SNAP-25 in t-SNAREs of intracellular membranes? Here we show that an intracellular t-SNARE is built from a ‘heavy chain’ homologous to syntaxin and two separate non-syntaxin ‘light chains’. SNAP-25 may thus be the exception rather than the rule, having been derived from genes that encoded separate light chains that fused during evolution to produce a single gene encoding one protein with two helices.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    et al. SNAP receptors implicated in vesicle targeting and fusion. Nature 362, 318–324 (1993).

  2. 2.

    et al. SNAREpins: minimal machinery for membrane fusion. Cell 92, 759–772 ( 1998).

  3. 3.

    , , & Crystal structure of a SNARE complex involved in synaptic exocytosis at 2.4 Å resolution. Nature 395, 347–353 (1998).

  4. 4.

    , & Syntaxin: a synaptic protein implicated in docking of synaptic vesicles at presynaptic active zones. Science 257, 255–259 (1992).

  5. 5.

    et al. The identification of a novel synaptosomal-associated protein, SNAP-25, differentially expressed by neuronal subpopulations. J. Cell Biol. 109, 3039–3052 (1989).

  6. 6.

    SNAREs and the secretory pathway-lessons from yeast. Exp. Cell Res. 247, 1–8 ( 1999).

  7. 7.

    , , , & Analysis of a yeast SNARE complex reveals remarkable similarity to the neuronal SNARE complex and a novel function for the C terminus of the SNAP-25 homolog, Sec9. J. Biol. Chem. 272, 16610–16617 ( 1997).

  8. 8.

    Prospore membrane formation defines a developmentally regulated branch of the secretory pathway in yeast. J. Cell Biol. 140, 29–37 (1998).

  9. 9.

    , , , & Homotypic vacuolar fusion mediated by t- and v-SNAREs. Nature 387, 199– 202 (1997).

  10. 10.

    & Vam7p, a vacuolar SNAP-25 homolog, is required for SNARE complex integrity and vacuole docking and fusion. EMBO J. 17, 3269–3276 ( 1998).

  11. 11.

    et al. Three v-SNAREs and two t-SNAREs, present in a pentameric cis-SNARE complex on isolated vacuoles, are essential for homotypic fusion. J. Cell Biol. 145, 1435– 1442 (1999).

  12. 12.

    , & Vam7p, a SNAP-25-like molecule, and Vam3p, a syntaxin homolog, function together in yeast vacuolar protein trafficking. Mol. Cell. Biol. 18, 5308–5319 (1998).

  13. 13.

    & SNAREs and membrane fusion in the Golgi apparatus. Biochim. Biophys. Acta 1404, 9–31 (1998).

  14. 14.

    , & The yeast v-SNARE Vti1p mediates two vesicle transport pathways through interactions with the t-SNAREs Sed5p and Pep12p. J. Cell Biol. 137, 1511–1524 (1997).

  15. 15.

    , & Use of resonance energy transfer to monitor membrane fusion. Biochemistry 20, 4093– 4099 (1981).

  16. 16.

    et al. Rapid and efficient fusion of phospholipid vesicles by the alpha-helical core of a SNARE complex in the absence of an N-terminal regulatory domain. Proc. Natl Acad. Sci. USA 96, 12565 –12570 (1999).

  17. 17.

    et al. Compartmental specificity of cellular membrane fusion encoded in SNARE proteins. Nature 407, 153– 159 (2000).

  18. 18.

    & Ca2+/calmodulin signals the completion of docking and triggers a late step of vacuole fusion. Nature 396, 575–580 ( 1998).

  19. 19.

    , , & A model for structural similarity between different SNARE complexes based on sequence relationships. Trends Cell Biol. 8, 260– 262 (1998).

  20. 20.

    & The Saccharomyces cerevisiae v-SNARE Vti1p is required for multiple membrane transport pathways to the vacuole. Mol. Biol. Cell 10, 1719 –1732 (1999).

  21. 21.

    , , & Protein interactions regulating vesicle transport between the endoplasmic reticulum and Golgi apparatus in mammalian cells. Cell 89, 149– 158 (1997).

  22. 22.

    , & Defining the functions of trans-SNARE pairs. Nature 396, 543–548 ( 1998).

  23. 23.

    et al. SNAREpins are functionally resistant to disruption by NSF and alpha-SNAP. J. Cell Biol. (in the press).

  24. 24.

    et al. Control of the terminal step of intracellular membrane fusion by protein phosphatase 1. Science 285, 1084 –1087 (1999).

  25. 25.

    , & Multiple methods of visualizing the yeast vacuole permit evaluation of its morphology and inheritance during the cell cycle. J. Cell Biol. 105, 1539–1547 (1987).

  26. 26.

    et al. Binary interactions of the SNARE proteins syntaxin-4, SNAP23, and VAMP-2 and their regulation by phosphorylation. Biochemistry 37, 11089–11096 ( 1998).

  27. 27.

    & Differential phosphorylation of syntaxin and synaptosome-associated protein of 25 kDa (SNAP–25) isoforms. J. Neurochem. 72, 614– 624 (1999).

  28. 28.

    et al. Ykt6p, a prenylated SNARE essential for endoplasmic reticulum–Golgi transport. J. Biol. Chem. 272, 17776 –17783 (1997).

  29. 29.

    et al. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) analysis of the lipid molecular species composition of yeast subcellular membranes reveals acyl chain-based sorting/remodeling of distinct molecular species en route to the plasma membrane. J. Cell Biol. 146, 741–754 (1999).

  30. 30.

    & Isolation and biochemical characterization of organelles from the yeast, Saccharomyces cerevisiae. Yeast 11, 493–536 ( 1995).

Download references


We wish to thank B. Brügger for preparation of the vacuolar lipid mixture and T. Wolfe for help with the manuscript. This work was supported by an NIH grant (to J.E.R.) and postdoctoral fellowships of the Japan Society for the Promotion of Science (to R.F.), the Human Frontiers Science Program Organization (to W.N.), the Deutsche Forschungsgemeinschaft (to T.E.), the Medical Research Council of Canada (to F.P.), the National Institutes of Health (to J.A.M.), the Swiss National Science Foundation (to T.W.) and the European Molecular Biology Organization (to T.W.).

Author information

Author notes

    • Ryouichi Fukuda
    • , James A. McNew
    • , Thomas Weber
    • , Thomas Engel
    •  & Walter Nickel

    Present addresses: Department of Biotechnology, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan (R.F); Department of Biochemistry and Cell Biology, Rice University, MS140, 6100 Main Street, PO Box 1892, Houston, Texas 77251-1892, USA (J.A.M.); Institute for Gene Therapy and Molecular Medicine, Box 1496, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, New York 10029-6574, USA (T.W.); Institut für Arterioskleroseforschung an der Westfälischen Wilhelms-Universität, Domagkstraße 3, D-48149 Münster, Germany (T.E.); Biochemie-Zentrum Heidelberg, Ruprecht-Karls-Universität , Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany (W.N.).


  1. Cellular Biochemistry & Biophysics Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, Box 519, New York, New York 10021, USA


  1. Search for Ryouichi Fukuda in:

  2. Search for James A. McNew in:

  3. Search for Thomas Weber in:

  4. Search for Francesco Parlati in:

  5. Search for Thomas Engel in:

  6. Search for Walter Nickel in:

  7. Search for James E. Rothman in:

  8. Search for Thomas H. Söllner in:

About this article

Publication history






Further reading Further reading


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.