Drosophila Amphiphysin is a Post-Synaptic Protein Required for Normal Locomotion but Not Endocytosis |
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Authors: | Peter A. Leventis Brenda M. Chow Bryan A. Stewart Balaji Iyengar Ana Regina Campos Gabrielle L. Boulianne |
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Affiliation: | Departments of Zoology and;Molecular and Medical Genetics, University of Toronto, Toronto, Canada;Program in Developmental Biology, The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada, M5G 1X8,;Department of Biology, McMaster University, Hamilton, Ontario, Canada, L8S 4K1;Current address: Division of Life Sciences, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ontario, Canada, M1C 1A4 |
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Abstract: | Clathrin-mediated endocytosis is required to recycle synaptic vesicles for fast and efficient neurotransmission. Amphiphysins are thought to be multiprotein adaptors that may contribute to this process by bringing together many of the proteins required for endocytosis. Their in vivo function, however, has yet to be determined. Here, we show that the Drosophila genome encodes a single amphiphysin gene that is broadly expressed during development. We also show that, unlike its vertebrate counterparts, Drosophila Amphiphysin is enriched postsynaptically at the larval neuromuscular junction. To determine the role of Drosophila Amphiphysin, we also generated null mutants which are viable but give rise to larvae and adults with pronounced locomotory defects. Surprisingly, the locomotory defects cannot be accounted for by alterations in the morphology or physiology of the neuromuscular junction. Moreover, using stimulus protocols designed to test endocytosis under moderate and extreme vesicle cycling, we could not detect any defect in the neuromuscular junction of the amphiphysin mutant. Taken together, our findings suggest that Amphiphysin is not required for viability, nor is it absolutely required for clathrin-mediated endocytosis. However, Drosophila Amphiphysin function is required in both larvae and adults for normal locomotion. |
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Keywords: | actin amphiphysin endocytosis synaptic vesicle recycling |
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