Fluorescence Resonance Energy Transfer Detection of Synaptophysin I and Vesicle-associated Membrane Protein 2 Interactions during Exocytosis from Single Live Synapses
AUTOR(ES)
Pennuto, Maria
FONTE
The American Society for Cell Biology
RESUMO
To investigate the molecular interactions of synaptophysin I and vesicle-associated membrane protein 2 (VAMP2)/synaptobrevin II during exocytosis, we have used time-lapse videomicroscopy to measure fluorescence resonance energy transfer in live neurons. For this purpose, fluorescent protein variants fused to synaptophysin I or VAMP2 were expressed in rat hippocampal neurons. We show that synaptophysin I and VAMP2 form both homo- and hetero-oligomers on the synaptic vesicle membrane. When exocytosis is stimulated with α-latrotoxin, VAMP2 dissociates from synaptophysin I even in the absence of appreciable exocytosis, whereas synaptophysin I oligomers disassemble only upon incorporation of the vesicle with the plasma membrane. We propose that synaptophysin I has multiple roles in neurotransmitter release, regulating VAMP2 availability for the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex and possibly participating in the late steps of exocytosis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=117936Documentos Relacionados
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