SNAP-25 (synaptosome-associated protein of 25,000 daltons) is a membrane bound protein anchored to the cytosolic face of membranes via palmitoyl side chains in the middle of the molecule. SNAP-25 is a Q-SNARE protein contributing two α-helices in the formation of the exocytotic fusion complex in neurons where it assembles with syntaxin-1 and synaptobrevin. SNAP-25 inhibits P/Q- and L-type voltage-gated calcium channels located presynaptically 1 and interacts with the synaptotagmin C2B domain in Ca2+-independent fashion 2. In glutamatergic synapses SNAP-25 decreases the Ca2+ responsiveness, while it is naturally absent in GABAergic synapses 3.
Consistent with the regulation of synaptic Ca2+ responsiveness, heterozygous deletion of the SNAP-25 gene in mice results in a hyperactive phenotype similar to attention deficit hyperactivity disorder (ADHD). In heterozygous mice, a decrease in hyperactivity is observed with dextroamphetamine (or Dexedrine), an active ingredient in the ADHD drug Adderall. Homozygous deletions of the SNAP-25 gene are lethal. Subsequent studies have suggested that at least some of the SNAP-25 gene mutations in humans might predispose to ADHD 45.
Botulinum toxins A, C and E cleave SNAP-25 6 leading to paralysis in clinically developed botulism.
Molecular machinery driving exocytosis in neuromediator release. The core SNARE complex is formed by four α-helices contributed by synaptobrevin, syntaxin and SNAP-25, synaptotagmin serves as a Ca
2+ sensor and regulates intimately the SNARE zipping.
References
- ^ Hodel A (1998). "SNAP-25". The International Journal of Biochemistry & Cell Biology 30 (10): 1069–1073. doi:10.1016/S1357-2725(98)00079-X.
- ^ Chapman ER (2002). "Synaptotagmin: A Ca2+ sensor that triggers exocytosis?". Nature Reviews Molecular Cell Biology 3: 498–508.
- ^ Pozzi D, Verderio C, Patti L, Grumelli C, Inverardi F, Frassoni C, Bonanno G, Matteoli M (2004). "SNAP-25 modulation of calcium dynamics underlies differences in GABAergic and glutamatergic responsiveness to depolarization". Neuron 41 (4): 599–610. doi:10.1016/S0896-6273(04)00077-7.
- ^ Brophy K, Hawi Z, Kirley A, Fitzgerald M, Gill M (2002). "Synaptosomal-associated protein 25 (SNAP-25) and attention deficit hyperactivity disorder (ADHD): evidence of linkage and association in the Irish population". Molecular Psychiatry 7 (8): 913–917. doi:10.1038/sj.mp.4001092.
- ^ Mill J, Curran S, Kent L, Gould A, Huckett L, Richards S, Taylor E, Asherson P (2002). "Association study of a SNAP-25 microsatellite and attention deficit hyperactivity disorder". American Journal of Medical Genetics 114 (3): 269–271. doi:10.1002/ajmg.10253.
- ^ Aoki KR, Guyer B (2001). "Botulinum toxin type A and other botulinum toxin serotypes: a comparative review of biochemical and pharmacological actions". European Journal of Neurology 8: 21–29. doi:10.1046/j.1468-1331.2001.00035.x.
Further reading
- Hanson PI, Otto H, Barton N, Jahn R (1995). "The N-ethylmaleimide-sensitive fusion protein and alpha-SNAP induce a conformational change in syntaxin.". J. Biol. Chem. 270 (28): 16955–61. PMID 7622514.
- Hata Y, Südhof TC (1995). "A novel ubiquitous form of Munc-18 interacts with multiple syntaxins. Use of the yeast two-hybrid system to study interactions between proteins involved in membrane traffic.". J. Biol. Chem. 270 (22): 13022–8. PMID 7768895.
- Chapman ER, An S, Barton N, Jahn R (1994). "SNAP-25, a t-SNARE which binds to both syntaxin and synaptobrevin via domains that may form coiled coils.". J. Biol. Chem. 269 (44): 27427–32. PMID 7961655.
- Zhao N, Hashida H, Takahashi N, Sakaki Y (1994). "Cloning and sequence analysis of the human SNAP25 cDNA.". Gene 145 (2): 313–4. PMID 8056350.
- Bark IC, Wilson MC (1994). "Human cDNA clones encoding two different isoforms of the nerve terminal protein SNAP-25.". Gene 139 (2): 291–2. PMID 8112622.
- Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides.". Gene 138 (1-2): 171–4. PMID 8125298.
- Maglott DR, Feldblyum TV, Durkin AS, Nierman WC (1996). "Radiation hybrid mapping of SNAP, PCSK2, and THBD (human chromosome 20p).". Mamm. Genome 7 (5): 400–1. PMID 8661740.
- Ravichandran V, Chawla A, Roche PA (1996). "Identification of a novel syntaxin- and synaptobrevin/VAMP-binding protein, SNAP-23, expressed in non-neuronal tissues.". J. Biol. Chem. 271 (23): 13300–3. PMID 8663154.
- Rettig J, Sheng ZH, Kim DK, et al. (1996). "Isoform-specific interaction of the alpha1A subunits of brain Ca2+ channels with the presynaptic proteins syntaxin and SNAP-25.". Proc. Natl. Acad. Sci. U.S.A. 93 (14): 7363–8. PMID 8692999.
- Jagadish MN, Fernandez CS, Hewish DR, et al. (1996). "Insulin-responsive tissues contain the core complex protein SNAP-25 (synaptosomal-associated protein 25) A and B isoforms in addition to syntaxin 4 and synaptobrevins 1 and 2.". Biochem. J. 317 ( Pt 3): 945–54. PMID 8760387.
- Betz A, Okamoto M, Benseler F, Brose N (1997). "Direct interaction of the rat unc-13 homologue Munc13-1 with the N terminus of syntaxin.". J. Biol. Chem. 272 (4): 2520–6. PMID 8999968.
- Araki S, Tamori Y, Kawanishi M, et al. (1997). "Inhibition of the binding of SNAP-23 to syntaxin 4 by Munc18c.". Biochem. Biophys. Res. Commun. 234 (1): 257–62. doi:10.1006/bbrc.1997.6560. PMID 9168999.
- Lane SR, Liu Y (1997). "Characterization of the palmitoylation domain of SNAP-25.". J. Neurochem. 69 (5): 1864–9. PMID 9349529.
- Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library.". Gene 200 (1-2): 149–56. PMID 9373149.
- Okamoto M, Südhof TC (1998). "Mints, Munc18-interacting proteins in synaptic vesicle exocytosis.". J. Biol. Chem. 272 (50): 31459–64. PMID 9395480.
- Low SH, Roche PA, Anderson HA, et al. (1998). "Targeting of SNAP-23 and SNAP-25 in polarized epithelial cells.". J. Biol. Chem. 273 (6): 3422–30. PMID 9452464.
- Poirier MA, Hao JC, Malkus PN, et al. (1998). "Protease resistance of syntaxin.SNAP-25.VAMP complexes. Implications for assembly and structure.". J. Biol. Chem. 273 (18): 11370–7. PMID 9556632.
- Prekeris R, Klumperman J, Chen YA, Scheller RH (1998). "Syntaxin 13 mediates cycling of plasma membrane proteins via tubulovesicular recycling endosomes.". J. Cell Biol. 143 (4): 957–71. PMID 9817754.
- Gonelle-Gispert C, Halban PA, Niemann H, et al. (1999). "SNAP-25a and -25b isoforms are both expressed in insulin-secreting cells and can function in insulin secretion.". Biochem. J. 339 ( Pt 1): 159–65. PMID 10085240.
- Ilardi JM, Mochida S, Sheng ZH (1999). "Snapin: a SNARE-associated protein implicated in synaptic transmission.". Nat. Neurosci. 2 (2): 119–24. doi:10.1038/5673. PMID 10195194.
External links
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Membrane protein: vesicular transport proteins |
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SNAP-25 - Syntaxin ( STX1A, STX1B, STX2, STX3, STX4, STX5, STX6, STX7, STX8, STX10, STX11, STX12, STX16, STX17, STX18, STX19) - Synaptobrevin
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