title: Dbo/Henji Modulates Synaptic dPAK to Gate Glutamate Receptor Abundance and Postsynaptic Response.
abstract: In response to environmental and physiological changes, the synapse manifests plasticity while simultaneously maintains homeostasis. Here, we analyzed mutant synapses of henji, also known as dbo, at the Drosophila neuromuscular junction (NMJ). In henji mutants, NMJ growth is defective with appearance of satellite boutons. Transmission electron microscopy analysis indicates that the synaptic membrane region is expanded. The postsynaptic density (PSD) houses glutamate receptors GluRIIA and GluRIIB, which have distinct transmission properties. In henji mutants, GluRIIA abundance is upregulated but that of GluRIIB is not. Electrophysiological results also support a GluR compositional shift towards a higher IIA/IIB ratio at henji NMJs. Strikingly, dPAK, a positive regulator for GluRIIA synaptic localization, accumulates at the henji PSD. Reducing the dpak gene dosage suppresses satellite boutons and GluRIIA accumulation at henji NMJs. In addition, dPAK associated with Henji through the Kelch repeats which is the domain essential for Henji localization and function at postsynapses. We propose that Henji acts at postsynapses to restrict both presynaptic bouton growth and postsynaptic GluRIIA abundance by modulating dPAK.
authors.affiliation: Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Manyu
authors.initials: M
authors.lastname: Wang
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.|Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Pei-Yi
authors.initials: PY
authors.lastname: Chen
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.|Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chien-Hsiang
authors.initials: CH
authors.lastname: Wang
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.|Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Tzu-Ting
authors.initials: TT
authors.lastname: Lai
authors.affiliation: Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Pei-I
authors.initials: PI
authors.lastname: Tsai
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Ying-Ju
authors.initials: YJ
authors.lastname: Cheng
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Hsiu-Hua
authors.initials: HH
authors.lastname: Kao
authors.affiliation: Institute of Molecular Medicine, National Taiwan University, Taipei, Taiwan.|Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.|Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Cheng-Ting
authors.initials: CT
authors.lastname: Chien
mesh_terms: D000818:Animals; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics / Q000648:ultrastructure; D000071776:Kelch Repeat / Q000235:genetics; D046529:Microscopy, Electron, Transmission; D009469:Neuromuscular Junction / Q000235:genetics* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism; D017470:Receptors, Glutamate / Q000235:genetics*; D058468:Receptors, Ionotropic Glutamate / Q000235:genetics*; D013569:Synapses / Q000235:genetics* / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000235:genetics; D054462:p21-Activated Kinases / Q000235:genetics*
chemical_list: D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; D017470:Receptors, Glutamate; D058468:Receptors, Ionotropic Glutamate; C000618220:glutamate receptor IIA, Drosophila; C000618221:glutamate receptor IIB, Drosophila; C099277:Pak protein, Drosophila; D054462:p21-Activated Kinases