Source:http://linkedlifedata.com/resource/pubmed/id/10849215
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
7
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| pubmed:dateCreated |
2000-7-19
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| pubmed:abstractText |
In mammals, the synaptosomal-associated protein of 25 kDa, SNAP-25, is generally thought to play a role in synaptic exocytosis of neuronal messengers. Using a polyclonal antiserum against rat SNAP-25, we have shown the presence of a SNAP-25-like protein in the brain of the South-African clawed toad Xenopus laevis by Western blotting and immunocytochemistry. Xenopus SNAP-25 is ubiquitously present throughout the brain, where its distribution in various identified neuronal perikarya and axon tracts is described. Western blot analysis and immunocytochemistry also demonstrated the presence of SNAP-25 in the neural, intermediate and distal lobes of the pituitary gland. Intensity line plots of confocal laser scanning microscope images of isolated melanotropes indicated that SNAP-25 is produced and processed in the rough endoplasmatic reticulum and Golgi apparatus, and is associated with the plasma membrane. Immunoelectron microscopy substantiated the idea that SNAP-25 is present in the plasma membrane but also showed a close association of SNAP-25 with the bounding membrane of peptide-containing secretory granules in both the neurohemal axon terminals in the neural lobe and the endocrine melanotropes in the intermediate lobe. Quantitative Western blotting revealed that adapting Xenopus to a dark background has a clear stimulatory effect on the expression of SNAP-25 in the neural lobe and in the melanotrope cells. This background light intensity-dependent stimulation of SNAP-25 expression was confirmed by the demonstration of increased immunofluorescence recorded by confocal laser scanning microscopy of individual melanotropes of black background-adapted toads. On the basis of this study on Xenopus laevis, we conclude that SNAP-25 (i) plays a substantial role in the secretion of a wide variety of neuronal messengers; (ii) functions in the central nervous system but also in neurohormonal and endocrine systems; (iii) acts at the plasma membrane but possibly also at the membrane of synaptic vesicles and peptide-containing secretory granules; (iv) acts not only locally (as in synapses), but at various sites of the plasma membrane (as in the endocrine melanotrope cell); and (v) can be upregulated in its expression by physiological stimuli that increase the extent of the molecular machinery involved in exocytosis.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical | |
| pubmed:status |
MEDLINE
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| pubmed:month |
Jul
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| pubmed:issn |
0953-8194
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
12
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
694-706
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| pubmed:dateRevised |
2005-11-17
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| pubmed:meshHeading |
pubmed-meshheading:10849215-Animals,
pubmed-meshheading:10849215-Blotting, Western,
pubmed-meshheading:10849215-Brain,
pubmed-meshheading:10849215-Exocytosis,
pubmed-meshheading:10849215-Immunohistochemistry,
pubmed-meshheading:10849215-Membrane Proteins,
pubmed-meshheading:10849215-Nerve Tissue Proteins,
pubmed-meshheading:10849215-Pituitary Gland,
pubmed-meshheading:10849215-Subcellular Fractions,
pubmed-meshheading:10849215-Synaptosomal-Associated Protein 25,
pubmed-meshheading:10849215-Tissue Distribution,
pubmed-meshheading:10849215-Xenopus laevis
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| pubmed:year |
2000
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| pubmed:articleTitle |
Localization and physiological regulation of the exocytosis protein SNAP-25 in the brain and pituitary gland of Xenopus laevis.
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| pubmed:affiliation |
Department of Cellular Animal Physiology, Nijmegen Institute for Neurosciences, University of Nijmegen, The Netherlands. smkolk@sci.kun.nl
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| pubmed:publicationType |
Journal Article
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