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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
1
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pubmed:dateCreated |
2005-2-28
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pubmed:abstractText |
The neuronal SNARE complex formed by synaptobrevin, syntaxin and SNAP-25 plays a central role in Ca2+-triggered neurotransmitter release. The SNARE complex contains several potential Ca2+-binding sites on the surface, suggesting that the SNAREs may be involved directly in Ca2+-binding during release. Indeed, overexpression of SNAP-25 bearing mutations in two putative Ca2+ ligands (E170A/Q177A) causes a decrease in the Ca2+-cooperativity of exocytosis in chromaffin cells. To test whether the SNARE complex might function in Ca2+-sensing, we analyzed its Ca2+-binding properties using transverse relaxation optimized spectroscopy (TROSY)-based NMR methods. Several Ca2+-binding sites are found on the surface of the SNARE complex, but most of them are not specific for Ca2+ and all have very low affinity. Moreover, we find that the E170A/Q177A SNAP-25 mutation does not alter interactions between the SNAREs and the Ca2+ sensor synaptotagmin 1, but severely impairs SNARE complex assembly. These results suggest that the SNAREs do not act directly as Ca2+ receptors but SNARE complex assembly is coupled tightly to Ca2+-sensing during neurotransmitter release.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0022-2836
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
18
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pubmed:volume |
347
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
145-58
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:15733924-Binding Sites,
pubmed-meshheading:15733924-Biosensing Techniques,
pubmed-meshheading:15733924-Calcium,
pubmed-meshheading:15733924-Calcium-Binding Proteins,
pubmed-meshheading:15733924-Membrane Glycoproteins,
pubmed-meshheading:15733924-Mutation,
pubmed-meshheading:15733924-Nerve Tissue Proteins,
pubmed-meshheading:15733924-Neurons,
pubmed-meshheading:15733924-Nuclear Magnetic Resonance, Biomolecular,
pubmed-meshheading:15733924-Protein Binding,
pubmed-meshheading:15733924-Protein Structure, Secondary,
pubmed-meshheading:15733924-Recombinant Fusion Proteins,
pubmed-meshheading:15733924-SNARE Proteins,
pubmed-meshheading:15733924-Synaptotagmin I,
pubmed-meshheading:15733924-Synaptotagmins,
pubmed-meshheading:15733924-Vesicular Transport Proteins
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pubmed:year |
2005
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pubmed:articleTitle |
Are neuronal SNARE proteins Ca2+ sensors?
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pubmed:affiliation |
Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
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