Essential role of endophilin A in synaptic vesicle budding at the Drosophila neuromuscular junction.
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.
Guichet
Antoine
A
Laboratory of Developmental Biology, Institut Jacques Monod, 2 place Jussieu, F-75251 Paris Cedex 05, France.
Wucherpfennig
Tanja
T
Dudu
Veronica
V
Etter
Sylvain
S
Wilsch-Bräuniger
Michaela
M
Hellwig
Andrea
A
González-Gaitán
Marcos
M
Huttner
Wieland B
WB
Schmidt
Anne A
AA
D000214:Acyl Coenzyme A / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002490:Central Nervous System / Q000378:metabolism; D018076:DNA, Complementary; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster; D004705:Endocytosis; D015870:Gene Expression; D008246:Lysophospholipids / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009469:Neuromuscular Junction / Q000378:metabolism / Q000502:physiology*; D010641:Phenotype; D017729:Presynaptic Terminals / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013572:Synaptic Vesicles / Q000378:metabolism / Q000502:physiology*; D018909:src Homology Domains
D000214:Acyl Coenzyme A; D018076:DNA, Complementary; D029721:Drosophila Proteins; D008246:Lysophospholipids; D000217:Acyltransferases; C456023:endophilin A, Drosophila; C018764:2-acylglycerophosphate acyltransferase