Prodomain removal enables neto to stabilize glutamate receptors at the Drosophila neuromuscular junction.
Stabilization of neurotransmitter receptors at postsynaptic specializations is a key step in the assembly of functional synapses. Drosophila Neto (Neuropillin and Tolloid-like protein) is an essential auxiliary subunit of ionotropic glutamate receptor (iGluR) complexes required for the iGluRs clustering at the neuromuscular junction (NMJ). Here we show that optimal levels of Neto are crucial for stabilization of iGluRs at synaptic sites and proper NMJ development. Genetic manipulations of Neto levels shifted iGluRs distribution to extrajunctional locations. Perturbations in Neto levels also produced small NMJs with reduced synaptic transmission, but only Neto-depleted NMJs showed diminished postsynaptic components. Drosophila Neto contains an inhibitory prodomain that is processed by Furin1-mediated limited proteolysis. neto null mutants rescued with a Neto variant that cannot be processed have severely impaired NMJs and reduced iGluRs synaptic clusters. Unprocessed Neto retains the ability to engage iGluRs in vivo and to form complexes with normal synaptic transmission. However, Neto prodomain must be removed to enable iGluRs synaptic stabilization and proper postsynaptic differentiation.
Program in Cellular Regulation and Metabolism, NICHD, NIH, Bethesda, Maryland, United States of America.
Young-Jun
YJ
Kim
Program in Cellular Regulation and Metabolism, NICHD, NIH, Bethesda, Maryland, United States of America.
Oghomwen
O
Igiesuorobo
Program in Cellular Regulation and Metabolism, NICHD, NIH, Bethesda, Maryland, United States of America.
Cathy I
CI
Ramos
Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America.
Hong
H
Bao
Division of Biological Sciences, University of Missouri, Columbia, Missouri, United States of America.
Bing
B
Zhang
Program in Cellular Regulation and Metabolism, NICHD, NIH, Bethesda, Maryland, United States of America.
Mihaela
M
Serpe
D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development*; D007814:Larva; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009469:Neuromuscular Junction / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D034622:RNA Interference; D058468:Receptors, Ionotropic Glutamate / Q000235:genetics / Q000378:metabolism*; D013569:Synapses / Q000235:genetics / Q000378:metabolism; D009435:Synaptic Transmission / Q000235:genetics
D029721:Drosophila Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; C573279:Neto protein, Drosophila; D058468:Receptors, Ionotropic Glutamate