title: Collaboration of PSD-Zip70 with its binding partner, SPAR, in dendritic spine maturity.
abstract: Recent studies have reported on the molecular mechanisms underlying dendritic spine (spine) dynamics. Because most of these studies investigated spine dynamics by overexpressing constitutively active or dominant-negative PSD (postsynaptic density) proteins in cultured mature neurons, the results represent the enlargement of mature spines or their return to an immature state. Here, we developed the technique of in utero electroporation to investigate spine dynamics. Using this technique, we demonstrated the suppression of spine maturation by the C-terminal variants of PSD-Zip70 in vitro and in vivo. Transient overexpression of the C terminus of PSD-Zip70 and knock-down of PSD-Zip70 also displayed the destabilization of mature spines. We further found the PSD-Zip70 and SPAR (spine-associated RapGAP) interaction via the short C-terminal region of PSD-Zip70 and the GK-binding domain of SPAR. In association with immature spines induced by overexpression of the PSD-Zip70 C terminus or knock-down of PSD-Zip70, SPAR lost its spine localization. Overexpression of the GK-binding domain of SPAR also induced to form immature spines without affecting the localization of PSD-Zip70 in the small heads of filopodial spines. Our results suggest that PSD-Zip70 in collaboration with SPAR is critically involved in spine maturity, especially in the mature spine formation and the maintenance of spine maturity.
authors.affiliation: Department of Neuroscience, Osaka University Graduate School of Medicine, Suita City, Osaka 565-0871, Japan.
authors.forename: Hisato
authors.initials: H
authors.lastname: Maruoka
authors.forename: Daijiro
authors.initials: D
authors.lastname: Konno
authors.forename: Kei
authors.initials: K
authors.lastname: Hori
authors.forename: Kenji
authors.initials: K
authors.lastname: Sobue
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology / Q000196:embryology; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure*; D018274:Electroporation / Q000379:methods*; D005260:Female; D005326:Fetal Proteins / Q000737:chemistry / Q000502:physiology; D020690:GTPase-Activating Proteins / Q000737:chemistry / Q000502:physiology*; D018390:Gene Targeting; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D005865:Gestational Age; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D007276:Injections, Intraventricular; D051379:Mice; D008813:Mice, Inbred ICR; D008845:Microinjections; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D011247:Pregnancy; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D011554:Pseudopodia / Q000378:metabolism / Q000648:ultrastructure; D014162:Transfection
chemical_list: D005326:Fetal Proteins; D020690:GTPase-Activating Proteins; C475881:Lzts1 protein, rat; D009419:Nerve Tissue Proteins; C479629:Sipa1l1 protein, rat; D049452:Green Fluorescent Proteins