Essential role of endophilin A in synaptic vesicle budding at the Drosophila neuromuscular junction

• Published in: The EMBO journal 2002-04, Vol.21 (7), p.1661-1672
• Main Authors: Guichet, Antoine, Wucherpfennig, Tanja, Dudu, Veronica, Etter, Sylvain, Wilsch-Bräuniger, Michaela, Hellwig, Andrea, González-Gaitán, Marcos, Huttner, Wieland B., Schmidt, Anne A.
• Format: Article
• Language: English
• Subjects: 2-Acylglycerophosphate acyltransferase; acid acyl transferase; Acyl Coenzyme A - metabolism; Acyltransferases - genetics; Acyltransferases - metabolism; Amino Acid Sequence; Animals; Base Sequence; Central Nervous System - metabolism; clathrin; DNA, Complementary; Drosophila; Drosophila melanogaster; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; dynamin; EMBO20; EMBO27; Endocytosis; endophilin; endophilin A; Gene Expression; Larvae; Lysophospholipids - metabolism; membrane curvature; membrane lipids; Mice; Molecular Sequence Data; Mutagenesis; Mutants; Neuromuscular Junction - metabolism; Neuromuscular Junction - physiology; Phenotype; Presynaptic Terminals - metabolism; Sequence Homology, Amino Acid; src Homology Domains; synaptic vesicles; Synaptic Vesicles - metabolism; Synaptic Vesicles - physiology
• ISSN: 0261-4189; 1460-2075; 1460-2075
• DOI: 10.1093/emboj/21.7.1661

We characterized Drosophila endophilin A (D‐endoA), and generated and analysed D‐endoA mutants. Like its mammalian homologue, D‐endoA exhibits lysophosphatidic acid acyl transferase activity and contains a functional SH3 domain. D‐endoA is recruited to the sites of endocytosis, as revealed by immunocytochemistry of the neuromuscular junction (NMJ) of mutant L3 larvae carrying the temperature‐sensitive allele of dynamin, shibire . D‐endoA null mutants show severe defects in motility and die at the early L2 larval stage. Mutants with reduced D‐endoA levels exhibit a range of defects of synaptic vesicle endocytosis, as observed at L3 larvae NMJs using FM1‐43 uptake and electron microscopy. NMJs with an almost complete loss of synaptic vesicles did not show an accumulation of intermediates of the budding process, whereas NMJs with only slightly reduced levels of synaptic vesicles showed a striking increase in early‐stage, but not late‐stage, budding intermediates at the plasma membrane. Together with results of previous studies, these observations indicate that endophilin A is essential for synaptic vesicle endocytosis, being required from the onset of budding until fission.