title: Nectin-dependent localization of ZO-1 at puncta adhaerentia junctions between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of adult mouse hippocampus.
abstract: Nectin and afadin constitute a novel intercellular adhesion system that organizes adherens junctions in cooperation with the cadherin-catenin system in epithelial cells. Nectin is a Ca(2+)-independent immunoglobulin-like adhesion molecule and afadin is an actin filament (F-actin)-binding protein that connects nectin to the actin cytoskeleton. At the puncta adhaerentia junctions (PAs) between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of the adult mouse hippocampus, the nectin-afadin system also colocalizes with the cadherin-catenin system and has a role in the formation of synapses. ZO-1 is another F-actin-binding protein that localizes at tight junctions (TJs) and connects claudin to the actin cytoskeleton in epithelial cells. The nectin-afadin system is able to recruit ZO-1 to the nectin-based cell-cell adhesion sites in nonepithelial cells that have no TJs. In the present study, we investigated the localization of ZO-1 in the mouse hippocampus. Immunofluorescence and immunoelectron microscopy revealed that ZO-1 also localized at the PAs between the mossy fiber terminals and the dendrites of the pyramidal cells in the CA3 area of the adult mouse hippocampus, as described for afadin. ZO-1 colocalized with afadin during the development of synaptic junctions and PAs. Microbeads coated with the extracellular fragment of nectin, which interacts with cellular nectin, recruited both afadin and ZO-1 to the bead-cell contact sites in cultured rat hippocampal neurons. These results indicate that ZO-1 colocalizes with nectin and afadin at the PAs and that the nectin-afadin system is involved in the localization of ZO-1.
authors.affiliation: Department of Molecular Biology and Biochemistry, Osaka University Graduate School of Medicine/Faculty of Medicine, Suita 565-0871, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Inagaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Irie
authors.forename: Maki
authors.initials: M
authors.lastname: Deguchi-Tawarada
authors.forename: Wataru
authors.initials: W
authors.lastname: Ikeda
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Ohtsuka
authors.forename: Masakazu
authors.initials: M
authors.lastname: Takeuchi
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D018929:Cell Culture Techniques; D003712:Dendrites / Q000737:chemistry; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000737:chemistry / Q000254:growth & development; D016547:Kinesins; D008565:Membrane Proteins / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008840:Microfilament Proteins / Q000032:analysis; D016253:Microscopy, Immunoelectron; D019599:Mossy Fibers, Hippocampal / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D009218:Myosins; D000075983:Nectins; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D017729:Presynaptic Terminals / Q000737:chemistry* / Q000378:metabolism; D017966:Pyramidal Cells / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000737:chemistry; D062826:Zonula Occludens-1 Protein
chemical_list: C490657:Afdn protein, mouse; D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D008840:Microfilament Proteins; D000075983:Nectins; D010750:Phosphoproteins; C569043:Tjp1 protein, mouse; C569044:Tjp1 protein, rat; D062826:Zonula Occludens-1 Protein; C108835:afadin; D009218:Myosins; D016547:Kinesins