Fast synaptic fatigue in shibire mutants reveals a rapid requirement for dynamin in synaptic vesicle membrane trafficking.
The GTPase dynamin is involved in endocytosis in many cell types, as first revealed by temperature-sensitive paralytic mutations in the Drosophila dynamin gene, shibire (shi), which disrupt synaptic vesicle endocytosis and deplete synaptic terminals of vesicles. Here we report that shi synapses exhibit a fast synaptic fatigue phenotype within 20 ms of repetitive stimulation, which cannot be explained by vesicle depletion, as we confirmed by electron microscopy. These results suggest that, in addition to its well-characterized role in synaptic vesicle recycling, dynamin may be required for short-term maintenance of the readily releasable pool of synaptic vesicles.
Kawasaki
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F
Department of Biology, 208 Mueller Laboratory, Penn State University, University Park, Pennsylvania 16802, USA.
Hazen
M
M
Ordway
R W
RW
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D002462:Cell Membrane / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000378:metabolism*; D034281:Dynamins; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism*; D008854:Microscopy, Electron; D009046:Motor Neurons / Q000378:metabolism / Q000648:ultrastructure; D018763:Muscle Fatigue / Q000502:physiology*; D009469:Neuromuscular Junction / Q000378:metabolism / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000378:metabolism* / Q000648:ultrastructure; D013997:Time Factors
D029721:Drosophila Proteins; D020558:GTP Phosphohydrolases; D034281:Dynamins; C439628:shi protein, Drosophila