Abstract
Neurotransmitter release from synaptic vesicles is triggered by voltage-gated calcium influx through P/Q-type or N-type calcium channels. Purification of N-type channels from rat brain synaptosomes initially suggested molecular interactions between calcium channels and two key proteins implicated in exocytosis: synaptotagmin I and syntaxin 1. Co-immunoprecipitation experiments were consistent with the hypothesis that both N- and P/Q-type calcium channels, but not L-type channels, are associated with the 7S complex containing syntaxin 1, SNAP-25, VAMP and synaptotagmin I or II. Immunofluorescence confocal microscopy at the frog neuromuscular junction confirmed that calcium channels, syntaxin 1 and SNAP-25 are co-localized at active zones of the presynaptic plasma membrane where transmitter release occurs. Experiments with recombinant proteins were performed to map synaptic protein interaction sites on the alpha 1A subunit, which forms the pore of the P/Q-type calcium channel. In vitro-translated 35S-synaptotagmin I bound to a site located on the cytoplasmic loop linking homologous domains II and III of the alpha 1A subunit. This direct link would target synaptotagmin, a putative calcium sensor for exocytosis, to a microdomain of calcium influx close to the channel mouth. Cysteine string proteins (CSPs) contain a J-domain characteristic of molecular chaperones that cooperate with Hsp70. They are located on synaptic vesicles and thought to be involved in modulating the activity of presynaptic calcium channels. CSPs were found to bind to the same domain of the calcium channel as synaptotagmin, and also to associate with VAMP. CSPs may act as molecular chaperones in association with Hsp70 to direct assembly or dissociation of multiprotein complexes at the calcium channel.
Full Text
The Full Text of this article is available as a PDF (179.9 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adler E. M., Augustine G. J., Duffy S. N., Charlton M. P. Alien intracellular calcium chelators attenuate neurotransmitter release at the squid giant synapse. J Neurosci. 1991 Jun;11(6):1496–1507. doi: 10.1523/JNEUROSCI.11-06-01496.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bennett M. K., Calakos N., Scheller R. H. Syntaxin: a synaptic protein implicated in docking of synaptic vesicles at presynaptic active zones. Science. 1992 Jul 10;257(5067):255–259. doi: 10.1126/science.1321498. [DOI] [PubMed] [Google Scholar]
- Bezprozvanny I., Scheller R. H., Tsien R. W. Functional impact of syntaxin on gating of N-type and Q-type calcium channels. Nature. 1995 Dec 7;378(6557):623–626. doi: 10.1038/378623a0. [DOI] [PubMed] [Google Scholar]
- Boudier J. A., Charvin N., Boudier J. L., Fathallah M., Tagaya M., Takahashi M., Seagar M. J. Distribution of components of the SNARE complex in relation to transmitter release sites at the frog neuromuscular junction. Eur J Neurosci. 1996 Mar;8(3):545–552. doi: 10.1111/j.1460-9568.1996.tb01239.x. [DOI] [PubMed] [Google Scholar]
- Brose N., Petrenko A. G., Südhof T. C., Jahn R. Synaptotagmin: a calcium sensor on the synaptic vesicle surface. Science. 1992 May 15;256(5059):1021–1025. doi: 10.1126/science.1589771. [DOI] [PubMed] [Google Scholar]
- Chamberlain L. H., Burgoyne R. D. The molecular chaperone function of the secretory vesicle cysteine string proteins. J Biol Chem. 1997 Dec 12;272(50):31420–31426. doi: 10.1074/jbc.272.50.31420. [DOI] [PubMed] [Google Scholar]
- Charvin N., L'evêque C., Walker D., Berton F., Raymond C., Kataoka M., Shoji-Kasai Y., Takahashi M., De Waard M., Seagar M. J. Direct interaction of the calcium sensor protein synaptotagmin I with a cytoplasmic domain of the alpha1A subunit of the P/Q-type calcium channel. EMBO J. 1997 Aug 1;16(15):4591–4596. doi: 10.1093/emboj/16.15.4591. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Garcia E. P., McPherson P. S., Chilcote T. J., Takei K., De Camilli P. rbSec1A and B colocalize with syntaxin 1 and SNAP-25 throughout the axon, but are not in a stable complex with syntaxin. J Cell Biol. 1995 Apr;129(1):105–120. doi: 10.1083/jcb.129.1.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geppert M., Goda Y., Hammer R. E., Li C., Rosahl T. W., Stevens C. F., Südhof T. C. Synaptotagmin I: a major Ca2+ sensor for transmitter release at a central synapse. Cell. 1994 Nov 18;79(4):717–727. doi: 10.1016/0092-8674(94)90556-8. [DOI] [PubMed] [Google Scholar]
- Gundersen C. B., Umbach J. A. Suppression cloning of the cDNA for a candidate subunit of a presynaptic calcium channel. Neuron. 1992 Sep;9(3):527–537. doi: 10.1016/0896-6273(92)90190-o. [DOI] [PubMed] [Google Scholar]
- Hayashi T., McMahon H., Yamasaki S., Binz T., Hata Y., Südhof T. C., Niemann H. Synaptic vesicle membrane fusion complex: action of clostridial neurotoxins on assembly. EMBO J. 1994 Nov 1;13(21):5051–5061. doi: 10.1002/j.1460-2075.1994.tb06834.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heckmann M., Adelsberger H., Dudel J. Evoked transmitter release at neuromuscular junctions in wild type and cysteine string protein null mutant larvae of Drosophila. Neurosci Lett. 1997 Jun 13;228(3):167–170. doi: 10.1016/s0304-3940(97)00390-x. [DOI] [PubMed] [Google Scholar]
- Heuser J. E., Reese T. S. Structural changes after transmitter release at the frog neuromuscular junction. J Cell Biol. 1981 Mar;88(3):564–580. doi: 10.1083/jcb.88.3.564. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Koh S., Yamamoto A., Inoue A., Inoue Y., Akagawa K., Kawamura Y., Kawamoto K., Tashiro Y. Immunoelectron microscopic localization of the HPC-1 antigen in rat cerebellum. J Neurocytol. 1993 Nov;22(11):995–1005. doi: 10.1007/BF01218356. [DOI] [PubMed] [Google Scholar]
- Leveque C., Hoshino T., David P., Shoji-Kasai Y., Leys K., Omori A., Lang B., el Far O., Sato K., Martin-Moutot N. The synaptic vesicle protein synaptotagmin associates with calcium channels and is a putative Lambert-Eaton myasthenic syndrome antigen. Proc Natl Acad Sci U S A. 1992 Apr 15;89(8):3625–3629. doi: 10.1073/pnas.89.8.3625. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li C., Ullrich B., Zhang J. Z., Anderson R. G., Brose N., Südhof T. C. Ca(2+)-dependent and -independent activities of neural and non-neural synaptotagmins. Nature. 1995 Jun 15;375(6532):594–599. doi: 10.1038/375594a0. [DOI] [PubMed] [Google Scholar]
- Llinás R., Sugimori M., Silver R. B. Microdomains of high calcium concentration in a presynaptic terminal. Science. 1992 May 1;256(5057):677–679. doi: 10.1126/science.1350109. [DOI] [PubMed] [Google Scholar]
- Lévêque C., el Far O., Martin-Moutot N., Sato K., Kato R., Takahashi M., Seagar M. J. Purification of the N-type calcium channel associated with syntaxin and synaptotagmin. A complex implicated in synaptic vesicle exocytosis. J Biol Chem. 1994 Mar 4;269(9):6306–6312. [PubMed] [Google Scholar]
- Martin-Moutot N., Charvin N., Leveque C., Sato K., Nishiki T., Kozaki S., Takahashi M., Seagar M. Interaction of SNARE complexes with P/Q-type calcium channels in rat cerebellar synaptosomes. J Biol Chem. 1996 Mar 22;271(12):6567–6570. doi: 10.1074/jbc.271.12.6567. [DOI] [PubMed] [Google Scholar]
- Mastrogiacomo A., Gundersen C. B. The nucleotide and deduced amino acid sequence of a rat cysteine string protein. Brain Res Mol Brain Res. 1995 Jan;28(1):12–18. doi: 10.1016/0169-328x(94)00172-b. [DOI] [PubMed] [Google Scholar]
- Matthews G. Neurotransmitter release. Annu Rev Neurosci. 1996;19:219–233. doi: 10.1146/annurev.ne.19.030196.001251. [DOI] [PubMed] [Google Scholar]
- McEnery M. W., Snowman A. M., Sharp A. H., Adams M. E., Snyder S. H. Purified omega-conotoxin GVIA receptor of rat brain resembles a dihydropyridine-sensitive L-type calcium channel. Proc Natl Acad Sci U S A. 1991 Dec 15;88(24):11095–11099. doi: 10.1073/pnas.88.24.11095. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mochida S., Sheng Z. H., Baker C., Kobayashi H., Catterall W. A. Inhibition of neurotransmission by peptides containing the synaptic protein interaction site of N-type Ca2+ channels. Neuron. 1996 Oct;17(4):781–788. doi: 10.1016/s0896-6273(00)80209-3. [DOI] [PubMed] [Google Scholar]
- Olivera B. M., Miljanich G. P., Ramachandran J., Adams M. E. Calcium channel diversity and neurotransmitter release: the omega-conotoxins and omega-agatoxins. Annu Rev Biochem. 1994;63:823–867. doi: 10.1146/annurev.bi.63.070194.004135. [DOI] [PubMed] [Google Scholar]
- Perin M. S., Fried V. A., Mignery G. A., Jahn R., Südhof T. C. Phospholipid binding by a synaptic vesicle protein homologous to the regulatory region of protein kinase C. Nature. 1990 May 17;345(6272):260–263. doi: 10.1038/345260a0. [DOI] [PubMed] [Google Scholar]
- Pupier S., Leveque C., Marqueze B., Kataoka M., Takahashi M., Seagar M. J. Cysteine string proteins associated with secretory granules of the rat neurohypophysis. J Neurosci. 1997 Apr 15;17(8):2722–2727. doi: 10.1523/JNEUROSCI.17-08-02722.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rettig J., Heinemann C., Ashery U., Sheng Z. H., Yokoyama C. T., Catterall W. A., Neher E. Alteration of Ca2+ dependence of neurotransmitter release by disruption of Ca2+ channel/syntaxin interaction. J Neurosci. 1997 Sep 1;17(17):6647–6656. doi: 10.1523/JNEUROSCI.17-17-06647.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Robitaille R., Adler E. M., Charlton M. P. Strategic location of calcium channels at transmitter release sites of frog neuromuscular synapses. Neuron. 1990 Dec;5(6):773–779. doi: 10.1016/0896-6273(90)90336-e. [DOI] [PubMed] [Google Scholar]
- Schiavo G., Gmachl M. J., Stenbeck G., Söllner T. H., Rothman J. E. A possible docking and fusion particle for synaptic transmission. Nature. 1995 Dec 14;378(6558):733–736. doi: 10.1038/378733a0. [DOI] [PubMed] [Google Scholar]
- Scott V. E., De Waard M., Liu H., Gurnett C. A., Venzke D. P., Lennon V. A., Campbell K. P. Beta subunit heterogeneity in N-type Ca2+ channels. J Biol Chem. 1996 Feb 9;271(6):3207–3212. doi: 10.1074/jbc.271.6.3207. [DOI] [PubMed] [Google Scholar]
- Scott V. E., Felix R., Arikkath J., Campbell K. P. Evidence for a 95 kDa short form of the alpha1A subunit associated with the omega-conotoxin MVIIC receptor of the P/Q-type Ca2+ channels. J Neurosci. 1998 Jan 15;18(2):641–647. doi: 10.1523/JNEUROSCI.18-02-00641.1998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sheng Z. H., Yokoyama C. T., Catterall W. A. Interaction of the synprint site of N-type Ca2+ channels with the C2B domain of synaptotagmin I. Proc Natl Acad Sci U S A. 1997 May 13;94(10):5405–5410. doi: 10.1073/pnas.94.10.5405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Smirnova T., Stinnakre J., Mallet J. Characterization of a presynaptic glutamate receptor. Science. 1993 Oct 15;262(5132):430–433. doi: 10.1126/science.8105537. [DOI] [PubMed] [Google Scholar]
- Söllner T., Whiteheart S. W., Brunner M., Erdjument-Bromage H., Geromanos S., Tempst P., Rothman J. E. SNAP receptors implicated in vesicle targeting and fusion. Nature. 1993 Mar 25;362(6418):318–324. doi: 10.1038/362318a0. [DOI] [PubMed] [Google Scholar]
- Südhof T. C., Rizo J. Synaptotagmins: C2-domain proteins that regulate membrane traffic. Neuron. 1996 Sep;17(3):379–388. doi: 10.1016/s0896-6273(00)80171-3. [DOI] [PubMed] [Google Scholar]
- Takahashi M., Arimatsu Y., Fujita S., Fujimoto Y., Kondo S., Hama T., Miyamoto E. Protein kinase C and Ca2+/calmodulin-dependent protein kinase II phosphorylate a novel 58-kDa protein in synaptic vesicles. Brain Res. 1991 Jun 14;551(1-2):279–292. doi: 10.1016/0006-8993(91)90942-o. [DOI] [PubMed] [Google Scholar]
- Umbach J. A., Gundersen C. B. Evidence that cysteine string proteins regulate an early step in the Ca2+-dependent secretion of neurotransmitter at Drosophila neuromuscular junctions. J Neurosci. 1997 Oct 1;17(19):7203–7209. doi: 10.1523/JNEUROSCI.17-19-07203.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Walch-Solimena C., Blasi J., Edelmann L., Chapman E. R., von Mollard G. F., Jahn R. The t-SNAREs syntaxin 1 and SNAP-25 are present on organelles that participate in synaptic vesicle recycling. J Cell Biol. 1995 Feb;128(4):637–645. doi: 10.1083/jcb.128.4.637. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Westenbroek R. E., Hell J. W., Warner C., Dubel S. J., Snutch T. P., Catterall W. A. Biochemical properties and subcellular distribution of an N-type calcium channel alpha 1 subunit. Neuron. 1992 Dec;9(6):1099–1115. doi: 10.1016/0896-6273(92)90069-p. [DOI] [PubMed] [Google Scholar]
- Wiser O., Tobi D., Trus M., Atlas D. Synaptotagmin restores kinetic properties of a syntaxin-associated N-type voltage sensitive calcium channel. FEBS Lett. 1997 Mar 10;404(2-3):203–207. doi: 10.1016/s0014-5793(97)00130-0. [DOI] [PubMed] [Google Scholar]
- Witcher D. R., De Waard M., Sakamoto J., Franzini-Armstrong C., Pragnell M., Kahl S. D., Campbell K. P. Subunit identification and reconstitution of the N-type Ca2+ channel complex purified from brain. Science. 1993 Jul 23;261(5120):486–489. doi: 10.1126/science.8392754. [DOI] [PubMed] [Google Scholar]
- Zinsmaier K. E., Eberle K. K., Buchner E., Walter N., Benzer S. Paralysis and early death in cysteine string protein mutants of Drosophila. Science. 1994 Feb 18;263(5149):977–980. doi: 10.1126/science.8310297. [DOI] [PubMed] [Google Scholar]
- Zinsmaier K. E., Hofbauer A., Heimbeck G., Pflugfelder G. O., Buchner S., Buchner E. A cysteine-string protein is expressed in retina and brain of Drosophila. J Neurogenet. 1990 Nov;7(1):15–29. doi: 10.3109/01677069009084150. [DOI] [PubMed] [Google Scholar]
- el Far O., Charvin N., Leveque C., Martin-Moutot N., Takahashi M., Seagar M. J. Interaction of a synaptobrevin (VAMP)-syntaxin complex with presynaptic calcium channels. FEBS Lett. 1995 Mar 13;361(1):101–105. doi: 10.1016/0014-5793(95)00156-4. [DOI] [PubMed] [Google Scholar]
- von Gersdorff H., Matthews G. Dynamics of synaptic vesicle fusion and membrane retrieval in synaptic terminals. Nature. 1994 Feb 24;367(6465):735–739. doi: 10.1038/367735a0. [DOI] [PubMed] [Google Scholar]