title: A cis-complex of NB-2/contactin-5 with amyloid precursor-like protein 1 is localized on the presynaptic membrane.
abstract: NB-2/contactin-5 plays an important role in synapse formation in the developing auditory system of rodents. In this study, to further elucidate the molecular role of NB-2 in synapse formation, we examined the interaction between NB-2 and amyloid precursor-like protein 1 (APLP1), as well as their possible co-localization at the synapse. Pull-down assays and cell surface binding assays demonstrated that NB-2 interacts with APLP1. Furthermore, the protein expression profile of APLP1 in western blots was similar to that of NB-2, and localization of APLP1 mRNA partially overlapped that of NB-2 mRNA. In cultured hippocampal neurons, immunofluorescence signals for both NB-2 and APLP1 overlapped with synapsin, a presynaptic marker. Biochemical analysis showed that both NB-2 and APLP1 were enriched in the presynaptic fraction. These results indicate that NB-2 forms a cis-complex with APLP1 on the presynaptic membrane.
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, 1603-1 Kamitomiokamachi, Nagaoka, Niigata 940-2188, Japan. shimo@vos.nagaokaut.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shimoda
authors.forename: Fumiya
authors.initials: F
authors.lastname: Koseki
authors.forename: Masaki
authors.initials: M
authors.lastname: Itoh
authors.forename: Manabu
authors.initials: M
authors.lastname: Toyoshima
authors.forename: Kazutada
authors.initials: K
authors.lastname: Watanabe
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002478:Cells, Cultured; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000378:metabolism; D017403:In Situ Hybridization; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013570:Synaptic Membranes / Q000378:metabolism*
chemical_list: D016564:Amyloid beta-Protein Precursor; C078201:Aplp1 protein, mouse; D015816:Cell Adhesion Molecules, Neuronal; C545358:NB-2 protein, mouse; D011993:Recombinant Fusion Proteins