TY - JOUR
T1 - Fluorescence resonance energy transfer detection of synaptophysin I and vesicle-associated membrane protein 2 interactions during exocytosis from single live synapses
AU - Pennuto, Maria
AU - Dunlap, David
AU - Contestabile, Andrea
AU - Benfenati, Fabio
AU - Valtorta, Flavia
PY - 2002/8
Y1 - 2002/8
N2 - To investigate the molecular interactions of synaptophysin I and vesicle-associated membrane protein 2 (VAMP2)/synaptobrevin II during exocytosis, we have used time-lapse videomicros-copy 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 1 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.
AB - To investigate the molecular interactions of synaptophysin I and vesicle-associated membrane protein 2 (VAMP2)/synaptobrevin II during exocytosis, we have used time-lapse videomicros-copy 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 1 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.
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U2 - 10.1091/mbc.E02-01-0036
DO - 10.1091/mbc.E02-01-0036
M3 - Article
C2 - 12181340
AN - SCOPUS:0036679152
VL - 13
SP - 2706
EP - 2717
JO - Molecular Biology of the Cell
JF - Molecular Biology of the Cell
SN - 1059-1524
IS - 8
ER -